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fuel injector testing


OnyxWalker

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OnyxWalker

Hi,

 

I was just wondering if oil heads had a problem with fuel injectors? I bought a R1150 engine ( running supposedly , Not for me ) and when I checked the resistance of the injectors I get nothing no resistance and no fuel when its connected.

So I went and bought 2 more from another supposed running bike and I get the same thing, no resistance and no fuel. 

Before I loose it on cycle barn can someone please verify that no resistance on the injector terminal does indeed guarantee that the injector is no good.

 

 

Thanks for any help.

 

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dirtrider
8 minutes ago, OnyxWalker said:

Hi,

 

I was just wondering if oil heads had a problem with fuel injectors? I bought a R1150 engine ( running supposedly , Not for me ) and when I checked the resistance of the injectors I get nothing no resistance and no fuel when its connected.

So I went and bought 2 more from another supposed running bike and I get the same thing, no resistance and no fuel. 

Before I loose it on cycle barn can someone please verify that no resistance on the injector terminal does indeed guarantee that the injector is no good.

 

 

Thanks for any help.

 

Afternoon  OnyxWalker

 

What resistance scale are you measuring on?  Those injectors will have some resistance but it will be low. As long as they are not open (infinity) then they are probably good. (try the 2K scale)

 

Are you seeing injection pulses across your injector plug terminal when you crank the engine?    

 

Do you have 12v going to the injectors during engine cranking?

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OnyxWalker

Hi Dr 

yes when the fuel pump primes i have 12 v at the plug, green wire.

The lowest value i have is 20k when I test a 5.1 k resistor its spot on, my injectors s.t goes to 0.02

 According to bosch there should be 15.95 ohms

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dirtrider
1 hour ago, OnyxWalker said:

Hi Dr 

yes when the fuel pump primes i have 12 v at the plug, green wire.

The lowest value i have is 20k when I test a 5.1 k resistor its spot on, my injectors s.t goes to 0.02

 According to bosch there should be 15.95 ohms

Afternoon  OnyxWalker

 

Well if you don't have a lower ohmmeter setting (like 200 ohms) then you probably should do something like a current flow test through the injector.  

 

Put 12v on one pin of the injector then see if it will light a 12v test light on the other injector pin (won't light full bright but should at least glow enough to see).

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OnyxWalker

I put 12v on one of the injector terminals and a test light on the other and the light got dimmer but only slightly.

 

S.t else i noticed was when i put my test light on the green wire ( the one which connects to the fuel pump relay ) and turn on the ignition I get power while the pump is priming but when I turn over the motor I get nothing from that lead?

 

I'm just a bit hung up on the fact I might have 4 crapped injectors, hard to believe. but if not the injector it can only be the ECU correct.

 

D.r you once mentioned using an led to test voltage coming from the ECU to the injector, can I use any 12v led say like from a light strip?

 

If I dont get this engine started soon it'll sit for another year.

 

Thx

 

 

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dirtrider
24 minutes ago, OnyxWalker said:

I put 12v on one of the injector terminals and a test light on the other and the light got dimmer but only slightly.

 

S.t else i noticed was when i put my test light on the green wire ( the one which connects to the fuel pump relay ) and turn on the ignition I get power while the pump is priming but when I turn over the motor I get nothing from that lead?

 

I'm just a bit hung up on the fact I might have 4 crapped injectors, hard to believe. but if not the injector it can only be the ECU correct.

 

D.r you once mentioned using an led to test voltage coming from the ECU to the injector, can I use any 12v led say like from a light strip?

 

If I dont get this engine started soon it'll sit for another year.

 

Thx

 

 

Evening OnyxWalker

 

You can use any LED as long as it is a 12v LED, or it is resisted to function on 12v, just get the polarity correct. 

 

Your injectors sound like they are OK if they light a 12v test light. 

 

On the injector green wire having no power when cranking?--  that sort of  points to the HES, or a  Motronic issue. 

 

Any chance that your Motronic is locked out? Try removing fuse 5 for about 30 minutes, then re-install fuse 5, then turn the key to on (do not start engine), then twist the throttle a couple of times from idle to wide open throttle (that will re-learn the TPS).

 

Then see if your green wire stays at 12v during cranking.    

 

One more thing to check, there was a run of 1150R bikes that had an issue with the HES pigtail clip breaking, that could allow the HES wire harness to hit the alternator belt. (worth a quick look anyhow) 

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OnyxWalker

ok your not gonna wanna hear this but i have to tell you anyways, I had to cut the wire going to the HES to elongate it and just my luck I cut it on the rubber grommet where 6 wires turn into 4 , I soldered the wires and shrink wrapped twice than insulated and grounded. What think you of that?

Also at this point I should remind you the engine is in a plane  I will try re setting the motronic and the TPS and also I'm going to rig up an led.

Thanks for your help I'll let you know how it goes .

 

just wanted to add, of the HES signal wires I'm quite sure I got the neg - pos ok but of the 2 signal wires theres no way of knowing which is which after you cut them, I believe one is on top other on the bottom, does it make a difference if you mix these up?  

 

also, fuse 5 is the yellow - red stripe wire which gives 12v to the motronic?

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dirtrider
10 hours ago, OnyxWalker said:

ok your not gonna wanna hear this but i have to tell you anyways, I had to cut the wire going to the HES to elongate it and just my luck I cut it on the rubber grommet where 6 wires turn into 4 , I soldered the wires and shrink wrapped twice than insulated and grounded. What think you of that?

Also at this point I should remind you the engine is in a plane  I will try re setting the motronic and the TPS and also I'm going to rig up an led.

Thanks for your help I'll let you know how it goes .

 

just wanted to add, of the HES signal wires I'm quite sure I got the neg - pos ok but of the 2 signal wires theres no way of knowing which is which after you cut them, I believe one is on top other on the bottom, does it make a difference if you mix these up?  

 

also, fuse 5 is the yellow - red stripe wire which gives 12v to the motronic?

Morning  OnyxWalker

 

Your Motronic should have (2)  12v inputs, pin #23 should have full time 12v battery power (red/yellow wire).

Pin 1 should have ignition-switch-on 12v power (green/black wire).

 

It does make a difference on the HES sensor top vs bottom as far as running correctly as it effects ign timing, as well as effecting  injector spray timing,  BUT , even if backwards you should at least  get an injector trigger on each engine revolution.  


You definitely need to make (or buy) a "noid" light to put across the fuel injector connector terminals as that is a great way to tell if you are getting injector triggering from the Motronic.  (Google noid light).   A noid light is usually fairly cheap at your local auto parts store or online. 

 

If you have a timing light you might put a timing light on a spark plug wire then point into the timing hole while cranking to see if your spark is close to the TDC mark.  

 

You want to be very/very careful in modifying that HES wiring or you better be a great glider pilot. 

  • Haha 2
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OnyxWalker

just a quick follow up.. I made a tester from a light strip and when I turn on the ignition and the pump primes I get 2 quick flashes from the injector plug but when I crank I get nothing.

when i get home I'm going to do the reset and triple check my wiring from the HES and the tps cus I had to lengthen those as well.

 

cheers!

 

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dirtrider
4 minutes ago, OnyxWalker said:

just a quick follow up.. I made a tester from a light strip and when I turn on the ignition and the pump primes I get 2 quick flashes from the injector plug but when I crank I get nothing.

when i get home I'm going to do the reset and triple check my wiring from the HES and the tps cus I had to lengthen those as well.

 

cheers!

 

Morning  OnyxWalker

 

Your quick flashes indicate the Motronic drivers are capable of triggering the injectors. With no flashing while cranking that does (sort of) point to an HES issue.

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OnyxWalker

Hi.

so I double checked all the wiring and turned out I had the temp probes mixed up ( how important are those? ) and the brown wire from the tps was grounded, fixed all that and still the same.  every time I hit the ignition I hear the relay engage, the led flashes quick and thats it, when I crank - nothing, when I turn off the ignition the led once again gives a quick flash.

 

I'm charging up the batterie now, have another go at it after dinner.

 

just one thing according to Haynes theres a ground wire from the tps, I dont have that , I have just the four? also, on a motorcycle does the Hes plug into the harness just before the ecu and same for the oil temp sensor?

 

thx

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dirtrider
17 minutes ago, OnyxWalker said:

Hi.

so I double checked all the wiring and turned out I had the temp probes mixed up ( how important are those? ) and the brown wire from the tps was grounded, fixed all that and still the same.  every time I hit the ignition I hear the relay engage, the led flashes quick and thats it, when I crank - nothing, when I turn off the ignition the led once again gives a quick flash.

 

I'm charging up the batterie now, have another go at it after dinner.

 

just one thing according to Haynes theres a ground wire from the tps, I dont have that , I have just the four? also, on a motorcycle does the Hes plug into the harness just before the ecu and same for the oil temp sensor?

 

thx

Evening OnyxWalker

 

That ground wire to the TPS was attached to the L/H throttle body itself not in the TPS connector, or at the TPS proper. 

 

That TPS ground wire is not causing your lack of injection.

 

The oil temperature sensor is very important to engine starting & open loop operation. The AIT (Air Intake Temperature) sensor is much less important so it will start & run without that.

 

Difficult to tell much without being hands on but to me it still sort of points to an HES signal  issue.

 

Are you getting a spark while cranking?

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OnyxWalker

Evening,

yes I'm getting spark from all 4 , seems to me the oil temp plugged directly into the harness thats why I kept the plug.

just to be 100% the oil temp sensor is on top of the engine, sitting on the bike it would be on the right side, correct/

ok I'm going to check the oil sensor and wiring again.

 

Thanks D.r

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dirtrider
9 minutes ago, OnyxWalker said:

Evening,

yes I'm getting spark from all 4 , seems to me the oil temp plugged directly into the harness thats why I kept the plug.

just to be 100% the oil temp sensor is on top of the engine, sitting on the bike it would be on the right side, correct/

ok I'm going to check the oil sensor and wiring again.

 

Thanks D.r

Evening OnyxWalker

 

Yes, that is the oil temp sensor. 

 

Well if you are getting spark then at least part of your HES is working.  

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OnyxWalker

Hi Dr

 

I'm starting to think my problem is in the ECU side, I have a few wires coming from the main ECU plug which I cant seem to track on the wiring diagram.

 

Green with blue stripe-

Black with white stripe-

2 solid Brown 1.5 gauge-

2 Brown with grey stripe-

 

in the picture you see 3 wires taped in red, those are the coding plug wires ( Brown with peach, blue and green stripes ) I've left them open?  Also I was wondering if the Co2 sensor would have anything to do with injector pulse? I used a bosch aftermarket sensor which is supposed to be compatible but you never know..

 

Thanks  for all your help!

 

 

 

IMG_0162[1].JPG

IMG_0161[1].JPG

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dirtrider

Afternoon OnyxWalker

 

Can you tell me EXACTLY what BMW model & year that engine came out of? I will then try to track those wires down for you.

 

Unless your o2 sensor it totally shorted then it shouldn't have any effect on injector operation during engine cranking. 

 

The Green/Blue is for the fuel tank breather valve (emission control evap can purge)

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dirtrider
25 minutes ago, OnyxWalker said:

Afternoon,

 

The engine came out of a 2004 BMW R1150R , it has the dual spark.

OK, that will help_

 

The Green/Blue is for the fuel tank breather valve (emission control evap canister purge)

 

The Brown with grey stripe is for the low (sort of ground) for the  TPS (throttle position sensor) , oil temperature sensor, air intake temp sensor). These are very important for engine starting & running. 

 

The Black/White is the rear wheel speed sensor.

 

I can't seem to find a Brown 2.0mm wire, lots & lots of .35mm, 1mm , 2.5mm brown wires. On the BMW brown is always a ground but what your 2.0mm brown goes to is unknown at this time.  

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OnyxWalker

Hi Dr.

 

You mentioned all brown go to ground but if you look at the diagram all browns have specific terminals on the ECU plug.

I was just wondering if it makes a difference which ground goes where or if you can just randomly ground everything.

 

For instance the ground for the Timing sensor  goes to terminal 2 and is 1.5mm and the other 1.5mm brown wire coming from the harness goes to the side stand switch and back to terminal 34 on the motronic. If I mix these two up would that be a problem?

 

I'm pretty sure my problem is a ground somewhere, I've double checked all the wiring and switched around what I could and always remains the same ... no fuel pulse.

 

Also wanted to say , since connecting all those brown wires from the harness to the main ground my Led test light for the injectors got a lot brighter, but only when I hit the ignition switch.

 

Thanks.

 

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dirtrider
23 minutes ago, OnyxWalker said:

Hi Dr.

 

You mentioned all brown go to ground but if you look at the diagram all browns have specific terminals on the ECU plug.

I was just wondering if it makes a difference which ground goes where or if you can just randomly ground everything.

 

For instance the ground for the Timing sensor  goes to terminal 2 and is 1.5mm and the other 1.5mm brown wire coming from the harness goes to the side stand switch and back to terminal 34 on the motronic. If I mix these two up would that be a problem?

 

I'm pretty sure my problem is a ground somewhere, I've double checked all the wiring and switched around what I could and always remains the same ... no fuel pulse.

 

Also wanted to say , since connecting all those brown wires from the harness to the main ground my Led test light for the injectors got a lot brighter, but only when I hit the ignition switch.

 

Thanks.

 

Evening  OnyxWalker

 

Pretty much so BUT!, the proper way is to look at (go by) a credible wire diagram then make DARN SURE that each sensor or Motronic terminal with a brown wire  gets a ground point indicated on the wire diagram. Most just return to engine/trans/battery (-)  low (ground) but some could be different. 

 

I would make sure that any important engine sensors that show a common or combined  ground (or a Motronic return) get the SAME combined grounding point or Motronic return.

 

I hate trying to patch up or cut up an OEM wire harness. I usually strip it apart then run (& verify) each & every single wire per a credible wire diagram (no hidden tee'd in wires going to nothing,  or worse going to the wrong points that way).

 

This also gets rid of all those unneeded (future confusing) wires for brakes, lights, emission control items, etc.

 

 

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OnyxWalker

Going to match up all the brown wires with the terminal pin outs on the ECU, should have done that from the beginning for all the wires :(

 

Unfortunately I wasnt present when the engine was removed, and it was done quickie style.. but I do have all the plugs so I'm pretty confident the problem is at the ECU harness or maybe the ECU?  

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dirtrider
11 hours ago, OnyxWalker said:

Going to match up all the brown wires with the terminal pin outs on the ECU, should have done that from the beginning for all the wires :(

 

Unfortunately I wasnt present when the engine was removed, and it was done quickie style.. but I do have all the plugs so I'm pretty confident the problem is at the ECU harness or maybe the ECU?  

Morning OnyxWalker

 

Don't forget the .5mm (brown) ground wire that attaches to the L/H throttle body casting. That is shown in the wire diagrams but not defined very well. 

 

 

5fuRSGE.jpg

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OnyxWalker

Evening Dr, hope you had a nice day..

 

Yes I got him, but that brown-tan wire goes to a specific terminal on the ECU its not a common ground I dont think so not sure why it would be grounded to the engine?, Either way I'm pretty sure about him because on my Motronic wire harness I have a dedicated plug for the oil temp sensor and they share that ground or brown-tan wire. Unless he uses his own?

I'm really starting to get the feeling the problem is in those brown and brown-tan wires. Something else I just noticed , my Motronic plug has no numbers for the pin outs... any idea where I could find those or another way to trace the wires?

 

 

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dirtrider
6 minutes ago, OnyxWalker said:

Evening Dr, hope you had a nice day..

 

Yes I got him, but that brown-tan wire goes to a specific terminal on the ECU its not a common ground I dont think so not sure why it would be grounded to the engine?, Either way I'm pretty sure about him because on my Motronic wire harness I have a dedicated plug for the oil temp sensor and they share that ground or brown-tan wire. Unless he uses his own?

I'm really starting to get the feeling the problem is in those brown and brown-tan wires. Something else I just noticed , my Motronic plug has no numbers for the pin outs... any idea where I could find those or another way to trace the wires?

 

 

Evening  OnyxWalker

 

That throttle body ground point grounds to the engine/trans stud NOT back to the Motronic, it is a brown wire not a brown/tan or brown/grey. It's purpose I believe is to remove static RFI buildup from high speed air passing through the throttle body.

 

Don't confuse with the brown/grey wire going to the TPS, air temp, oil temp as that isn't an actual engine or battery (-)  ground, it is actually a sensor circuit low returning back to the the Motronic. 

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OnyxWalker

Good day sir...

 

So last night I went through it wire by wire and dont ask me what I changed cus I'm not quite sure but now I have pulse on the injectors when cranking. 

My only issue is that I dont get the injector quick pulse when I turn on the ignition, the fuel pump primes but no flashes on my LED test light. Before I put everything back together and connect the fuel lines I just wanted to be sure this is ok.

I'm not using a Motronic relay so my wiring from the ignition is a little different.  The ignition simply powers Pin 01 on the Motronic.

 

Thanks for the help!

 

 

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1 hour ago, OnyxWalker said:

Good day sir...

 

So last night I went through it wire by wire and dont ask me what I changed cus I'm not quite sure but now I have pulse on the injectors when cranking. 

My only issue is that I dont get the injector quick pulse when I turn on the ignition, the fuel pump primes but no flashes on my LED test light. Before I put everything back together and connect the fuel lines I just wanted to be sure this is ok.

I'm not using a Motronic relay so my wiring from the ignition is a little different.  The ignition simply powers Pin 01 on the Motronic.

 

Thanks for the help!

 

 

Afternoon  OnyxWalker

 

You don't really want an injector pulse at ignition-switch-on as that would give you a shot of fuel that isn't wanted or needed until engine cranking so you are good-to-go there. 

 

Do you get a fuel pump run prime for about 2 seconds at ignition-on? That is all you need at initial key-on. 

 

Personally I would use a Motronic fueling computer power relay, that serves 2 purposes, first it takes the Motronic load off of the ignition switch.  And 2nd it gives the Motronic more voltage than than going through the ignition switch with all the other ignition switch (on) accessory loads. 

 

If you are "not" going to use a relay then make darn sure you use a heavy duty ignition switch that can handle the circuit loads plus the Motronic loads & supply full power (use a large 2.0mm+ wire into the switch). BMW could have easily eliminated that Motronic's relay & used 12v B+  directly from the ignition switch but they chose to use a higher amp power relay to prevent problems (probably learned from Harley when they tried to eliminate the ignition system power relay & had to recall a bunch of motorcycles due to ignition switch failures with motorcycle dying while riding.   

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OnyxWalker

Hi Dr.

 

I'm starting to think its a fuel delivery problem, I get spray from the injectors but its very faint, almost hard to see unless you spray directly into a rag. And the original injectors that came with the engine are even worse, only drops come out.

This morning I tried with a bit of starter spray and it fired for a couple of seconds.

 

Does this sound like a dirty injector issue to you , and I was wondering  if its possible to get to the filter in the injector myself and see if its clogged or is it better to have them serviced by a injector cleaning shop.

 

Thanks. 

 

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35 minutes ago, OnyxWalker said:

Hi Dr.

 

I'm starting to think its a fuel delivery problem, I get spray from the injectors but its very faint, almost hard to see unless you spray directly into a rag. And the original injectors that came with the engine are even worse, only drops come out.

This morning I tried with a bit of starter spray and it fired for a couple of seconds.

 

Does this sound like a dirty injector issue to you , and I was wondering  if its possible to get to the filter in the injector myself and see if its clogged or is it better to have them serviced by a injector cleaning shop.

 

Thanks. 

 

Morning   OnyxWalker

 

It doesn't sound like dirty injector but it sure could be. 

 

It sounds way more like either low fuel pressure or not enough commanded fuel pulse width.

 

You can do a poor-mans fuel pressure test by disconnecting  the fuel return line, then plugging off the front half of the fuel return line (on the 1150 if it still has the quick disconnects it will plug itself off when disconnected)

 

Then turning the key to (on) & seeing how much fuel you have coming out of the fuel return line (note: on the 1150 if you still have the quick disconnects then you will have to hold the internal check valve open).

 

You will only get 2 seconds of fuel flow at key-on  so if no fuel in that 2 seconds crank the engine as that should run the fuel pump as long as the engine is cranking.

 

If it is making enough fuel flow at enough pressure you should get a pencil sized stream of fuel coming out of the fuel return line.  (fuel return is AFTER the fuel pressure regulator so if fuel coming from the return line then it is making enough pressure to open the 40psi+  pressure relief valve) 

 

Another test--- Once you have fuel pressure in the fuel manifold you can run 12v to one injector terminal (the green wire one) then short the other one to ground (or to battery negative post if using a standalone battery) . You should get a BIG spray of fuel. This  will  prove out injector function & lack of plugged injector. (CAUTION: point injector into container to prevent a large ball of fire) 

 

The commanded fuel spray is more difficult to test as that depends on the engine sensors & Motronic fueling map).    Prove out the fuel pressure & flow first, THEN if you have that look into the injector pulse width.

 

The big players in the cold cranking injector pulse width is the oil temperature sensor & the TPS sensor, with the Air Intake Sensor being a minor contributor. 

 

What are you using for a fuel pump on your set-up? If a remote fuel pump then it needs to be able to make 60psi+ fuel pressure. 

 

 

 

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OnyxWalker

Hi Dr,

 

I'm using clear fuel lines and I can see the fuel returning to the tank when the pump primes. And when I remove the injector theres lots of pressure behind it and probably leaks about 5 tablespoons of fuel. And like I mentioned the original injectors which have been sitting around for almost 10 years are completely blocked.

 

I'm going to try and clean 2 of the injectors with some lacquer thinner and brake fluid and see if it makes any difference.

 

If that doesnt work I have an adjustable fuel regulator I can try. 

The pump is new :)

 

Thanks again for all your help ..

 

P.s applying 12 volt to the injector before you remove it from the gas line is a GREAT TIP ! 

Before I was putting it in a plastic bag to avoid gas flying everywhere, your idea is MUCH better :)

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OnyxWalker

Hi Dr,

 

So I'm 90% sure I'm not getting enough voltage to the injectors or maybe pressure but I really dont think its pressure, my pump is a Quantum and its in the tank :)

The spray I get when cranking and when I apply 12v is not even close, at one point I disconnected one injector and the other side fired right up until the ECU realized it was only running on one cylinder and cut the fuel.

I'm going to beef up my ignition switch see if that helps. Also as you suggested I'm going to re-visit the TPS and oil temp sensor connections, anything else you can think of that would be giving me only enough voltage to fire 1 injector ? I've triple checked both injector plugs :) they're good.

 

I wanted to ask you.. according to my wiring diagram power to the ignition and fuel pump is connected to the moving terminal on the relay and the starter is on the fixed side... how important is this and is there a reason why the starter is wired differently?

 

Thanks for the help, hearing the motor fire has given me encouragement, I feel were close :) 

 

 

 

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1 hour ago, OnyxWalker said:

Hi Dr,

 

So I'm 90% sure I'm not getting enough voltage to the injectors or maybe pressure but I really dont think its pressure, my pump is a Quantum and its in the tank :)

The spray I get when cranking and when I apply 12v is not even close, at one point I disconnected one injector and the other side fired right up until the ECU realized it was only running on one cylinder and cut the fuel.

I'm going to beef up my ignition switch see if that helps. Also as you suggested I'm going to re-visit the TPS and oil temp sensor connections, anything else you can think of that would be giving me only enough voltage to fire 1 injector ? I've triple checked both injector plugs :) they're good.

 

I wanted to ask you.. according to my wiring diagram power to the ignition and fuel pump is connected to the moving terminal on the relay and the starter is on the fixed side... how important is this and is there a reason why the starter is wired differently?

 

Thanks for the help, hearing the motor fire has given me encouragement, I feel were close :) 

 

 

 

Evening  OnyxWalker

 

A lot to address in this one response. 

 

So I'm 90% sure I'm not getting enough voltage to the injectors--   Easy to measure voltage TO the injectors as that is a fixed system voltage (around 10v-12v constant during engine cranking or for 2 seconds at key on. Just measure voltage on green wire at injector. 

 

The injectors are actually supplied 12 v (or thereabouts) full time, the fuel injection itself is controlled by the Motronic grounding the low side of the injector for a controlled time period (called a pulse width). The longer the low side is pulled low (grounded the more fuel it sprays in)

 

Or maybe pressure but I really dont think its pressure, my pump is a Quantum and its in the tank :)--   Can this pump make & maintain 60 psi plus pressure? This is VERY IMPORTANT to your engine being able to start & run.

 

 

The spray I get when cranking and when I apply 12v is not even close, at one point I disconnected one injector and the other side fired right up until the ECU realized it was only running on one cylinder and cut the fuel.--   Your ECU (Motronic) doesn't have the ability to recognize it is only running on one cylinder so something else going on there. If you are low on fuel pressure or flow then disconnecting one side injector could allow j-u-s-t enough fuel to go to the remaining side injector to possibly give you a weak short fire-off. 

 

 

I'm going to beef up my ignition switch see if that helps.--   Either that or monitor voltage & voltage drops to see (IF) you are low on voltage in certain areas. Personally I am a monitor & find the PROBLEM  & it's root cause not a parts changer & hoper. 

 

Also as you suggested I'm going to re-visit the TPS and oil temp sensor connections, anything else you can think of that would be giving me only enough voltage to fire 1 injector ? I've triple checked both injector plugs :) they're good.--   DO NOT confuse injector voltage with injection performance, it is the low (ground side) that controls the injection pulse width. The longer the injector low side is pulled low the more fuel it sprays in. Just make sure the injector high (B+ ) side (green wire)   is close to system voltage & stays there.

 

The TPS must be wired & adjusted correctly as THAT is a very big player in cranking injector pulse width (fuel amount sprayed in). If it thinks you are at wide open throttle it could go into (clear enable) then turn the injector spray off thinking it is clearing a flooded engine condition.  At closed throttle the TPS output voltage (between pins 1 & 4)  needs to be under .399v (preferably around .365v) & at WOT it needs to be very close to 5 volts. Then once the the TPS  is adjusted the TPS needs to be registered to the Motronic  (Motronic needs to learn TPS idle & WOT positions). This is done either with a battery disconnect, or a fuse #5  removal for few minutes. THEN a battery reconnect (or fuse #5 re-install ). Then with ignition switch ON (engine not running) you need to move the throttle from idle to WOT about 3 times to re-learn the TPS positions.

 

The oil temp sensor also MUST be wired correctly & reporting the correct resistance back to the Motronic as that is BIG player in engine starting fuel injection spray amount.     

 

I wanted to ask you.. according to my wiring diagram power to the ignition and fuel pump is connected to the moving terminal on the relay and the starter is on the fixed side... how important is this and is there a reason why the starter is wired differently?--  It is only important IF your relays use a clipping diode instead of the more common clipping resistor. Look at the diagram on the side of the relay case to see if it has a resistor or diode across the pull in coil. Diode is directional & a resistor can work either direction to remove the back EMF spike at relay  pull-in coil collapse.  The relay  power control contact side will work OK either direction.  

 

 

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OnyxWalker

Just one more maybe obvious question.. I'm still getting zero ohms across my injectors, is it possible that 12v will activate them even though the coil inside the injector is pooched and giving me no resistance ?

 

To check pins 1-4 on the TPS I turn on ignition and test at the ECU?

 

I'm with you, learnt my lesson with the injectors, no more buying till I'm sure :)

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7 hours ago, OnyxWalker said:

Just one more maybe obvious question.. I'm still getting zero ohms across my injectors, is it possible that 12v will activate them even though the coil inside the injector is pooched and giving me no resistance ?

 

To check pins 1-4 on the TPS I turn on ignition and test at the ECU?

 

I'm with you, learnt my lesson with the injectors, no more buying till I'm sure :)

Morning    OnyxWalker

 

I'm still getting zero ohms across my injectors, is it possible that 12v will activate them even though the coil inside the injector is pooched and giving me no resistance ?--  I am REALLY/really/really questioning that 0 ohm resistance reading. Will they allow a 12v test light to light when put in series with test light???????????  If the coil inside the injector (both injectors, all of your injectors is (0) ohms then they are not open & they are not a coil). Re-evaluate your testing methods  or try another ohmmeter. 

 

To check pins 1-4 on the TPS I turn on ignition and test at the ECU?--  We usually check right at the TPS connector, if OK there then it wouldn't hurt to re-check at the Motronic (ECU)  connector.  With that 0 ohm reading above first make darn sure that your meter is working correctly.  

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Michaelr11
12 hours ago, OnyxWalker said:

 

To check pins 1-4 on the TPS I turn on ignition and test at the ECU?

 

Like DR says, test directly at the TPS connector.  The ignition has to be on, and the bike has to be ready to start - side stand up, kill switch in RUN position.

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43 minutes ago, Michaelr11 said:

 

Like DR says, test directly at the TPS connector.  The ignition has to be on, and the bike has to be ready to start - side stand up, kill switch in RUN position.

Afternoon  Michael 

 

I don't think his airplane has a side stand, at least I haven't ever seen a side stand on an airplane.  

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OnyxWalker

Morning Dr.  Lol

 

Ok ignition on , testing on the TPS connector removed I get 4.69 volts across pins 1-4.

When I attach the plug and test across 1-4 I get nothing, zero volts. no matter where I am with throttle position

 

Hi Michael, like Dr mentioned this engine is going in my ultralight

 

 

 

 

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1 hour ago, OnyxWalker said:

Morning Dr.  Lol

 

Ok ignition on , testing on the TPS connector removed I get 4.69 volts across pins 1-4.

When I attach the plug and test across 1-4 I get nothing, zero volts. no matter where I am with throttle position

 

Hi Michael, like Dr mentioned this engine is going in my ultralight

 

Afternoon   OnyxWalker

 

What voltage scale are you using on your meter? 

 

Are your SURE (darn sure) you have the TPS wired correctly? Terminal #1 is the 0 to1/2 throttle reference circuit. With connector plugged in it (#1 terminal) should start out (closed throttle) at just under .4 volts, then should go to about 5 volts at 1/2 open throttle up.

 

#2 terminal is (regulated)  5 volts into the TPS from the Motronic, 

 

#3 terminal is high throttle (full weep) reference back to the Motronic, 

 

#4 terminal is reference low (kind of a ground) returning to the Motronic. 

 

It isn't going to start if the TPS isn't wired & working correctly.

 

I'm not sure that wiring that TPS incorrectly could fry it unless you somehow got 12v into & through it  back to  ground.  

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OnyxWalker

Hi

 

I'm using 20v scale,

Its worth re mentioning that I only have 4 wires coming from my TPS.. white red , white-blue, green-yellow and the brown tan wire. I dont have a solid brown like it shows on the diagram. All these wires were attached according to the matching color wires from the ECU.

Re-set the motronic - same thing.

I'm going to have my local electronic supply store check the resistance of the injectors and let you know the result.

 

 

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3 minutes ago, OnyxWalker said:

Hi

 

I'm using 20v scale,

Its worth re mentioning that I only have 4 wires coming from my TPS.. white red , white-blue, green-yellow and the brown tan wire. I dont have a solid brown like it shows on the diagram. All these wires were attached according to the matching color wires from the ECU.

Re-set the motronic - same thing.

I'm going to have my local electronic supply store check the resistance of the injectors and let you know the result.

Afternoon   OnyxWalker

 

The solid brown wire hooks to that screw on the bottom of the L/H throttle body casting. 

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OnyxWalker

Hi,

I dont have a solid brown on my TPS. and the brown tan wire coming out of the sleeve of the TPS connector had a loop connector, which fits exactly to that screw you speak of , but grounding ( or attaching it there ) that brown tan wire cuts power to my injectors.

 

 

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7 minutes ago, OnyxWalker said:

Hi,

I dont have a solid brown on my TPS. and the brown tan wire coming out of the sleeve of the TPS connector had a loop connector, which fits exactly to that screw you speak of , but grounding that brown tan wire cuts power to my injectors.

 

 

Afternoon   OnyxWalker

 

That TB casting ground wire is a .5mm solid brown that went from the TB ground screw to a transmission case  ground   (engine ground) point. At least my BMW wire diagram shows it as a solid brown .5mm wire. 

 

If connecting that brown/tan wire to the TB causes an injector issue then either that is the wrong wire OR it  is not properly connected to the engine ground on the other end (ohm it out to see if it actually has a resistance free grounding point)

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OnyxWalker

Afternoon.

 

My diagram says the same but that solid brown is not there unless I'm blind?

Is the TB actually grounded? its secured to the engine with a rubber boot? just a thought..

 

P.s today I'm actually half blind, got s.t in my eye 2 days ago and wont come out, I'm going to the clinic at 3:00..lol

  • Sad 1
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2 minutes ago, OnyxWalker said:

Afternoon.

 

My diagram says the same but that solid brown is not there unless I'm blind?

Is the TB actually grounded? its secured to the engine with a rubber boot? just a thought..

Afternoon   OnyxWalker

 

The TB is not actually grounded without that brown ground wire attached as it is mounted between rubber boots.

 

It will (should) run without that brown ground wire attached but for long term TPS circuit protection you should probably add a ground wire between the L/H TB body & the engine case. 

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OnyxWalker

Got it !!

 

It will (should) run without that brown ground wire attached but for long term TPS circuit protection you should probably add a ground wire between the L/H TB body & the engine case

Nope, the brown wire coming from the TPS needs to be grounded. 

 

It clicked yesterday when you mentioned the TB was mounted between 2 rubber boots, as soon as I attached a proper ground to that bolt she fired right up and purrs like a kitten, those pipes sure get hot quick..lol

 

Now when I test between pins 1-4 on the TPS I get 0.044 volts and that number increases when I advance the throttle :)

 

Best Birthday present ever..lol   Thanks again for all your help, I knew we would get it!

 

 

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1 hour ago, OnyxWalker said:

Got it !!

 

It will (should) run without that brown ground wire attached but for long term TPS circuit protection you should probably add a ground wire between the L/H TB body & the engine case

Nope, the brown wire coming from the TPS needs to be grounded. 

 

It clicked yesterday when you mentioned the TB was mounted between 2 rubber boots, as soon as I attached a proper ground to that bolt she fired right up and purrs like a kitten, those pipes sure get hot quick..lol

 

Now when I test between pins 1-4 on the TPS I get 0.044 volts and that number increases when I advance the throttle :)

 

Best Birthday present ever..lol   Thanks again for all your help, I knew we would get it!

 

 

Afternoon OnyxWalker

 

I'm glad you have it running but I still do question that Brown wire needed to be hooked to the TB to allow running. 

 

Over the years I have seen a number of riders/home mechanics inadvertently  leave that TB ground wire disconnected & they still started & ran OK.  

 

If you look closely  (really break it down) the TPS & it's related circuits only require the # 1 through #4 connections to function  as THOSE supply the 5 volts in "#2" , supply the resistor circuit pull-to-low (ground) #4  & supply the two reference returns back to the Motroinic "#1 & #3".  That is ALL that is required to work correctly  so (to me)  it sort of looks like that external ground on the TB bolt is acting as a resistor low  in place of the correct  (brown/grey) #4 terminal wire. (at least you need to REALLY & FULLY  understand WHY you need the TB ground wire to run.   

 

My common sense  is sort of  telling me that you still have something wrong with the #4 (brown/grey) resistor low circuit, either being open, or not properly returning to the correct Motronic terminal.  Or possibly you are still missing a NEEDED Motronic ground wire to engine case  (basically to battery negative).  

 

If there is an issue with the #4  (Brown/grey) low circuit that could also be effecting the oil temp input & effecting the air temp input. It could run without those but not run correctly, especially after fully warming up, or under full load.  

 

Added: any chance that you have #4 terminal (brown/grey) wire mixed up with the (Brown only) TB bolt ground??

 

 

 

 

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Evening  OnyxWalker

 

As you can see in the below,  #1 through #4 should be all that is needed for proper TPS operation.

 

But #4 MUST return to the proper Motronic terminal & that circuit inside the Motronic must be working properly & have a proper low  in relation to the 5 volt supply circuit on pin 2. 

 

 

kPqyROH.jpg

 

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OnyxWalker

Hi

Yes I agree....But

If you are referring to the Haynes wiring diagram, that solid brown wire does not exist on my 2004 TPS.

 

What does exist is a Brown-Tan wire from pin 4 about 4 inches long with a loop connector at the end, perfect length. If that Brown-Tan wire is only connected to the TB bolt, when I measure across pins 1-4 ( plugged into the TPS using pins and ignition on ) I get 4.96 volts and it doesnt change when advancing the throttle. I think we can assume this is the 5v from the ECU blowing right through. When I ground the TB to the engine using that bolt I get 0.044v.

That Brown-Tan wire is also the common for the air and oil sensor, whether they will respond is yet to be seen.

 

 

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40 minutes ago, OnyxWalker said:

Hi

Yes I agree....But

If you are referring to the Haynes wiring diagram, that solid brown wire does not exist on my 2004 TPS.

 

What does exist is a Brown-Tan wire from pin 4 about 4 inches long with a loop connector at the end, perfect length. If that Brown-Tan wire is only connected to the TB bolt, when I measure across pins 1-4 ( plugged into the TPS using pins and ignition on ) I get 4.96 volts and it doesnt change when advancing the throttle. I think we can assume this is the 5v from the ECU blowing right through. When I ground the TB to the engine using that bolt I get 0.044v.

That Brown-Tan wire is also the common for the air and oil sensor, whether they will respond is yet to be seen.

Evening  OnyxWalker

 

About all I can tell you at the moment is based on my common sense & years of working on these things I'm having a difficult time understanding exactly where your problem is but I REALLY think you still have something wrong. 

 

My official BMW 1150r wiring diagram shows a .5mm total brown wire going to the TB bolt &  a brown/grey wire going to the TPS #4 terminal. 

You have it running but I'm not convinced that your have wired correctly.    

 

Added: one more thought-- It is possible that you have a TPS issue with the internal connection of #4 pin to the resistor lows. If this is the case then possibly it is using the TB external grounding as the resistor low now. 

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OnyxWalker

Evening,

 

Thats exactly what I have, only I had to add the solid brown myself. I'm sure if you look at any bike theres 2 brown ( 1 Br-Tan ) screwed to the TB, one goes to pin 4 on the TPS plug and the other is grounded somewhere on the bike...the only way.

Because I received only the motor , the person simply removed the ground going to the bike when they removed the engine. For example, had they simply cut that brown wire and left it attached I would have assumed it was a ground. Although the diagram does show a spot where these wires should be all screwed together I didnt put 2 and 2 together.

 

 

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3 minutes ago, OnyxWalker said:

Evening,

 

Thats exactly what I have, only I had to add the solid brown myself. I'm sure if you look at any bike theres 2 brown ( 1 Br-Tan ) screwed to the TB, one goes to pin 4 on the TPS plug and the other is grounded somewhere on the bike...the only way.

Because I received only the motor , the person simply removed the ground going to the bike when they removed the engine. For example, had they simply cut that brown wire and left it attached I would have assumed it was a ground. Although the diagram does show a spot where these wires should be all screwed together I didnt put 2 and 2 together.

 

 

Evening  OnyxWalker

 

I'm still not exactly sure what you have but just be sure that you TOTALLY understand the #4 low (ground) going back into the Motronic & the external TB grounding. If that #4 circuit isn't totally correct  it can really mess up your oil temp & air temp input into the Motronic. In open loop the Motronic bases a lot of it's fueling control on that oil temp sensor. 

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