Another no-spark issue

[jermaine_rider]

I have read numerous threads on this no spark issue common on 1100rt's, and I think I have consumed more than I need to. So my best option is to explain my issue and get some unique suggestions. My issue started when I changed the alternator belt. When installing it, I hit the HES wires and the bike wouldn't start. I did not know at the time that the HES wires go bad, and so I just played with the wires until the bike would start. Fast forward about two months. I'm riding down a long dark stretch of road and the bike shuts down. Had to push it a couple miles to the house. Figured it was the same issue so I played with the wires and it started. Another couple of months pass and I figure I should change the plugs. I do, and the bike is running bad. Hard to start. Poor fuel mileage. Backfires. Wont idle. Thought maybe it was the plugs so I got some different ones. No help. About a week of this and it refuses to start. I get a new hall sensor, more new plugs, and a pulley because I thought the pulley was one piece, not two,  and that mine had separated. Installed the HES, pretty sure I had it at TDC judging by the OT mark, put in the new plugs and had a friend weld the inside part of the pulley to the pulley itself. Found out that it is in fact two pieces and one is to be JB welded to the other, but, my problem is I have no spark. Coil is reading zero at the primary, 7500 at secondary. Fuel pump has always engaged when turning on the key, with or without the HES installed and plugged in. My question is what am I doing wrong or what could the issue be? I am beginning to get frustrated and if this doesn't get resolved soon, my next post will be 1998 R1100rt for sale. Thanks.

[dirtrider]

11 hours ago, jermaine_rider said:

I have read numerous threads on this no spark issue common on 1100rt's, and I think I have consumed more than I need to. So my best option is to explain my issue and get some unique suggestions. My issue started when I changed the alternator belt. When installing it, I hit the HES wires and the bike wouldn't start. I did not know at the time that the HES wires go bad, and so I just played with the wires until the bike would start. Fast forward about two months. I'm riding down a long dark stretch of road and the bike shuts down. Had to push it a couple miles to the house. Figured it was the same issue so I played with the wires and it started. Another couple of months pass and I figure I should change the plugs. I do, and the bike is running bad. Hard to start. Poor fuel mileage. Backfires. Wont idle. Thought maybe it was the plugs so I got some different ones. No help. About a week of this and it refuses to start. I get a new hall sensor, more new plugs, and a pulley because I thought the pulley was one piece, not two,  and that mine had separated. Installed the HES, pretty sure I had it at TDC judging by the OT mark, put in the new plugs and had a friend weld the inside part of the pulley to the pulley itself. Found out that it is in fact two pieces and one is to be JB welded to the other, but, my problem is I have no spark. Coil is reading zero at the primary, 7500 at secondary. Fuel pump has always engaged when turning on the key, with or without the HES installed and plugged in. My question is what am I doing wrong or what could the issue be? I am beginning to get frustrated and if this doesn't get resolved soon, my next post will be 1998 R1100rt for sale. Thanks.

Morning  

 

Coil is reading zero at the primary, 7500 at secondary-- "0" ohms is no good, how are you measuring the primary???  

 

What color is the coil? That makes a difference in the coil's resistance readings. In any case you need to see around  either .5 ohms or 1.0 ohms (depends on coil) at room temperature. 0 ohms is either a bad coil or incorrect measurement method. 

 

If you had the key on while fooling with, or working with,  the HES then try a #5 fuse removal for about 10 minutes, then re-install & see if it will start. On the 1100 you can inadvertently get a Motronic lock out if you induce non normal HES input.   

 

Are you getting 12v to the green wire at the coil with key-ON? 

[jermaine_rider]

The coil is the OEM colored black. I used a multimeter to test the primary by placing the probes on the primary prongs. I get continuity but a zero reading. I did test the green wire to the primary and I get 12v both with the key on and while starting it. I will try the #5 fuse removal and let you know how that works out.

[jermaine_rider]

I removed the #5 fuse for 10 minutes and put it back in nothing changed.

[dirtrider]

59 minutes ago, jermaine_rider said:

The coil is the OEM colored black. I used a multimeter to test the primary by placing the probes on the primary prongs. I get continuity but a zero reading. I did test the green wire to the primary and I get 12v both with the key on and while starting it. I will try the #5 fuse removal and let you know how that works out.

Afternoon jermaine_rider

 

Those black coils seldom fail but I suppose they can fail.

 

The primary on the black coil should be around 1.0 ohms at room temperature.  0 ohms of resistance would be pretty difficult as even with a shorted primary coil it should have s-o-m-e resistance. 

 

 

[jermaine_rider]

That being said, where do I go from here? Another question....I have read in similar threads that the fuel pump should run around 2-3 seconds when the key is turned on. Mine only runs for about 1-1.5 seconds. Not sure if that is relevant but something I noticed. 

[dirtrider]

11 minutes ago, jermaine_rider said:

That being said, where do I go from here? Another question....I have read in similar threads that the fuel pump should run around 2-3 seconds when the key is turned on. Mine only runs for about 1-1.5 seconds. Not sure if that is relevant but something I noticed. 

Afternoon jermaine_rider

 

1.5 seconds is plenty long to pressurize the fuel rail. 

 

That 1 on your meter (I presume is a digital meter) is probably showing an open. A lot of digital meters show 1 as infinity. 

 

Test an H7 headlight bulb with your meter if you have one, those are usually in the .4 to .6 ohm range. 

 

In any case, if your meter is working correctly & you don't show around 1.0 ohms resistance on the primary then your coil probably has an open (failed) primary).

 

Or power the coil's green wire terminal with 12v then use a 12v test light on the other primary terminal (test light should light if the primary OK). If it doesn't light then the primary is open (failed). 

 

Lots of BMW 1100 coils usually available on E-Bay just get the black one. 

[jermaine_rider]

OK I will test the primary and get back to you.

[jermaine_rider]

I put 12v to the green terminal on the coil and a test light to the other terminal on the coil and it lit up.

[dirtrider]

1 hour ago, jermaine_rider said:

I put 12v to the green terminal on the coil and a test light to the other terminal on the coil and it lit up.

Afternoon jermaine_rider

 

Then the primary has continuity so it should show some resistance reading. 

[jermaine_rider]

Ok perhaps I am doing something wrong there. Question about that pulley. There is a slotted sleeve inside the pulley should that opening be at either the top or bottom of the HES when initially installing it? I feel like there's something wrong with my HES installation. Haven't heard any concrete reasons for no spark and all this started when the HES went out on me.

[jermaine_rider]

Oh and I left out one thing, I replaced the oxygen sensor when it started backfiring and whatnot but it didn't help.

[dirtrider]

16 minutes ago, jermaine_rider said:

Ok perhaps I am doing something wrong there. Question about that pulley. There is a slotted sleeve inside the pulley should that opening be at either the top or bottom of the HES when initially installing it? I feel like there's something wrong with my HES installation. Haven't heard any concrete reasons for no spark and all this started when the HES went out on me.

Afternoon jermaine_rider

 

There is a tit on the timing cup that goes into the notch in the crankshaft (did you do that properly?)  That assures the correct timing cup lineup. 

 

Even so, if the timing cup is installed  correctly centered  in the HES (even if the clocking isn't correct) it SHOULD SPARK, probably not at the correct timing but still should spark someplace in the crankshaft rotation.

 

With the key ON does the fuel pump run for a couple of seconds as the crankshaft is turned one complete revolution? This at least verifies IF the HES is triggering the Motronic to run the fuel pump. 

 

[jermaine_rider]

Im not hearing anything from the fuel pump except when i turn the key on it engages. i put the bike in 5th gear and rotated the crankshaft with a 16mm socket clockwise and i hear nothing.

[jermaine_rider]

and yes that little tab on the timing cup is inserted into the slot on the crankshaft

 

[dirtrider]

16 minutes ago, jermaine_rider said:

Im not hearing anything from the fuel pump except when i turn the key on it engages. i put the bike in 5th gear and rotated the crankshaft with a 16mm socket clockwise and i hear nothing.

Evening jermaine_rider

 

The fuel pump should run for a couple of seconds as the timing notch in the cup passes the sensor. 

 

Is the HES fully connected? Once in a while plugging the connectors together can push a terminal pin back enough to lose contact. 

 

Otherwise you might have to remove the pulley again to verify the timing cup didn't tear up the HES sensor. 

 

Either that or build a timing box for the HES. 

[jermaine_rider]

Like you said I should still be getting spark and Im not. I took the pulley back off and made sure it was aligned and all that and still no spark

[dirtrider]

2 hours ago, jermaine_rider said:

Like you said I should still be getting spark and Im not. I took the pulley back off and made sure it was aligned and all that and still no spark

Afternoon jermaine_rider

 

We are getting into "need to be there" territory. 

 

If you have 12v to the coil green wire with key on, and the pulley timing cup is not contacting the HES & wrecking it,  then unless you have a wire terminal connection issue, or open wire between the HES & Motronic then it gest more difficult. 

 

It's possible you have a defective HES, it's also possible that when you damaged the HES wiring it fried the coil driver inside the Motronic, it's also possible that your coil is bad even though it ohm's out OK (not likely but you can't positively rule it out either).

 

Is the tachometer showing anything when you crank the engine? 

 

If you have a 12v test light then try unplugging the coil then put your 12v test light across the coil 12v B+ & trigger wire, then see if it flashes when you crank the engine. 

[jermaine_rider]

its possible the HES is defective as I bought it off Amazon. All I know is that when I unplug it the plug it back in the fuel pump kicks on briefly. But when I rotate the crankshaft with the HES installed and plugged in the fuel pump does not kick on at all. I am using the old pulley and am going to get a new one with that timing cup cuz the only thing that is different is that like I said a friend welded the timing cup to the inside of the pulley because I thought it was one piece that had broken off so that may be affecting how the HES recognizes the timing cup if that might have something to do with the spark then I guess Ill find out soon enough. If not then its either going in the shop or on FB Marketplace. Its been over two months and I am running out of patience. Thanks for all of the advise by the way. Hopefully this get get resolved soon.

[dirtrider]

16 minutes ago, jermaine_rider said:

its possible the HES is defective as I bought it off Amazon. All I know is that when I unplug it the plug it back in the fuel pump kicks on briefly. But when I rotate the crankshaft with the HES installed and plugged in the fuel pump does not kick on at all. I am using the old pulley and am going to get a new one with that timing cup cuz the only thing that is different is that like I said a friend welded the timing cup to the inside of the pulley because I thought it was one piece that had broken off so that may be affecting how the HES recognizes the timing cup if that might have something to do with the spark then I guess Ill find out soon enough. If not then its either going in the shop or on FB Marketplace. Its been over two months and I am running out of patience. Thanks for all of the advise by the way. Hopefully this get get resolved soon.

Afternoon jermaine_rider

 

You can try to use a strip of metal (like a feeler gauge) then move it through the HES sensor slots with the key turned on to see if you can get a spark or fuel pump run. 

[jermaine_rider]

I slid a razor blade inbetween the sensors on the HES while it was plugged in and got no response from the fuel  pump. One last question, can a used motronic replace the one I have or do they need to be programmed for the bike that they are installed on? Right now buying a bunch of new parts to trouble shoot isnt in my budget, but I also dont want to buy something if it isnt going to work at all. The HES is a brand new Bosch, and after all of the trouble shooting Ive done, its starting to point towards the motronic if its not the coil which you say is not as likely.

[dirtrider]

12 hours ago, jermaine_rider said:

I slid a razor blade inbetween the sensors on the HES while it was plugged in and got no response from the fuel  pump. One last question, can a used motronic replace the one I have or do they need to be programmed for the bike that they are installed on? Right now buying a bunch of new parts to trouble shoot isnt in my budget, but I also dont want to buy something if it isnt going to work at all. The HES is a brand new Bosch, and after all of the trouble shooting Ive done, its starting to point towards the motronic if its not the coil which you say is not as likely.

Morning   jermaine_rider

 

The fuel pump run & spark are timed differently.

 

The black coil failing probability is low, but even if it did that should not effect the fuel pump run part.

 

Are you getting (and maintaining) 12v B+ to the coil green wire throughout the engine cranking & starting process? It is possible that you are losing 12v to the fuel pump relay or that part of the circuit anyhow. If the coil green wire power is in question or intermittent then look into the side stand switch.  Also verify that fuse #5  is still good with continuity.  

 

During engine cranking the green wire to the coil & fuel injectors should remain on (ie have  12v).  

 

Just because the HES is new doesn't mean that it can't have an issue (things can & do slip though the post assembly test)

 

As far as Motronic's go, they are mostly the same as far as fit & basic running but there are different internal spark curves & updates over the 1100 model years. A new one from BMW would be a basic generic with latest firmware (kind of fit all). 

 

If you are buying a used Motronic from E-Bay (probably would) then try to find one from a similar 1100RT, an 1100R would work (run) but the firmware will probably be slightly different. When it comes to a replacement (used) Motronic's then I try to get close on year & try to at least get the same model (in your case RT).  

 

 

[jermaine_rider]

Thanks for your help. The green wire does maintain 12v while key is on and during cranking. I had a buddy use his meter on the coil and he couldnt get any reading on the secondary, while I was not able to get one on the primary. Guess neither of us know what we are doing in that respect. Im just still confused as to why I am getting no spark and no fuel pump action from the HES. I guess youre right it could be defective, which would make sense that nothing is working as it should. Guess Ill start there then tackle the problems as they arise after I install the new HES. Ill update once that is accomplished.

[jermaine_rider]

One other thing, I grounded a test light and put the probe to all of the wires on the HES while it was plugged in and when I touched the orange wire and black wire the fuel pump kicked on. Does that mean anything as far as HES working properly?

[dirtrider]

59 minutes ago, jermaine_rider said:

One other thing, I grounded a test light and put the probe to all of the wires on the HES while it was plugged in and when I touched the orange wire and black wire the fuel pump kicked on. Does that mean anything as far as HES working properly?

Afternoon  jermaine_rider

 

The orange goes to one of the HES sensors & the black goes to the other sensor. I haven't ever tried that (that I can remember anyhow)  but the probably means the Motronic can run the fuel pump relay IF it gets an HES signal. 

 

Do that test again & see if you can get a spark across a spark plug. 

[jermaine_rider]

Still no spark. And Im not getting any fuel squirting out of the injectors. Could I  have purchased a defective HES? I did get it brand new from Amazon for $100. Or did I just answer my own question?

[dirtrider]

11 hours ago, jermaine_rider said:

Still no spark. And Im not getting any fuel squirting out of the injectors. Could I  have purchased a defective HES? I did get it brand new from Amazon for $100. Or did I just answer my own question?

Morning jermaine_rider

 

Sure, you could have purchased a defective HES? There is a lot of previously returned problem parts sold on Amazon. 

 

Are you absolutely sure the pins inside the HES connector are ALL making good contact? 

 

Can you return the HES? If so try that.  

 

Your problem is king of boiling down to a problem with the HES, or a problem with the wiring between the Motronic & the HES, or a bad Motronic.  

 

 

[jermaine_rider]

Sorry for the late reply. Have you seen this diagram? It apparently is another way to test if the HES is working properly. HES wiring and test.pdf 

Well, I did as the man instructed and I have some curious results. Instead of hooking up the red wire directly to the battery I just left everything as is and just plugged the HES up like its supposed to be then I ran a positive from the LED to the battery and the negative to first the orange wire and then the black wire . With the key off, the LED is lit and when I pass something through the sensor nothing happens. The light stays on. Same thing with the black wire. Now, when I turn the key on, the LED goes out. When I pass something through the sensor again nothing happens. SO I was wondering, does that sound like im grounding out somewhere? Also, when I test the red wire on the harness on the bike side with the key on I get power, but when I plug the HES in and read it from the HES side of the harness, I get no reading. SO is it a wiring issue with the HES you think? I can accept that, if its wired wrong or I have a ground issue somewhere. ****UPDATE*** I removed the red wire from the HES harness and from the bike side harness. Put the LED positive to the bike side red wire and the LED negative to the red wire on the HES and the LED lights up. Wouldnt that suggest that the HES is wired wrong or grounding out somewhere? And when I didnt have the HES installed but had it plugged in the fuel pump kicked on and I had squirt from the injectors. Now that it is plugged in and mounted, back to square on. Nothing happening at all. 

Edited June 13 by jermaine_rider
added relevant info

[dirtrider]

6 hours ago, jermaine_rider said:

Sorry for the late reply. Have you seen this diagram? It apparently is another way to test if the HES is working properly. HES wiring and test.pdf 

Well, I did as the man instructed and I have some curious results. Instead of hooking up the red wire directly to the battery I just left everything as is and just plugged the HES up like its supposed to be then I ran a positive from the LED to the battery and the negative to first the orange wire and then the black wire . With the key off, the LED is lit and when I pass something through the sensor nothing happens. The light stays on. Same thing with the black wire. Now, when I turn the key on, the LED goes out. When I pass something through the sensor again nothing happens. SO I was wondering, does that sound like im grounding out somewhere? Also, when I test the red wire on the harness on the bike side with the key on I get power, but when I plug the HES in and read it from the HES side of the harness, I get no reading. SO is it a wiring issue with the HES you think? I can accept that, if its wired wrong or I have a ground issue somewhere. ****UPDATE*** I removed the red wire from the HES harness and from the bike side harness. Put the LED positive to the bike side red wire and the LED negative to the red wire on the HES and the LED lights up. Wouldnt that suggest that the HES is wired wrong or grounding out somewhere? And when I didnt have the HES installed but had it plugged in the fuel pump kicked on and I had squirt from the injectors. Now that it is plugged in and mounted, back to square on. Nothing happening at all. 

Morning  jermaine_rider

 

Yes, I have seen that test, in fact a LOT of us old time BMW riders have a test box that we built long ago.

 

First off, I am having a difficult time keeping up with your testing  method.  

 

First thing, make sure that your HES wires match the connector position (if you have a couple of wires switched in the connector it will never work correctly).

 

Then next, do that test as suggested (unplug from the motorcycle) & either use a remote battery or use leads from the motorcycle battery. With it still hooked to the motorcycle a problem in the Motronic can skew the test.  

[jermaine_rider]

Ok I will give that a shot. All of the wires are connected where they should be, I just separated the red wires to figure out why it was hot on one side and not the other when plugged in. I may have narrowed down the list of suspects. Remember when I told you s friend of mine welded that trigger inside of the pulley, well I think it's not either exactly straight or something because when I take the pulley off, things start working. When it's on, nothing works. I'll let you know what I come up with. I appreciate you hanging in there with me. Probably the longest most confusing post this year . 

[dirtrider]

1 hour ago, jermaine_rider said:

Ok I will give that a shot. All of the wires are connected where they should be, I just separated the red wires to figure out why it was hot on one side and not the other when plugged in. I may have narrowed down the list of suspects. Remember when I told you s friend of mine welded that trigger inside of the pulley, well I think it's not either exactly straight or something because when I take the pulley off, things start working. When it's on, nothing works. I'll let you know what I come up with. I appreciate you hanging in there with me. Probably the longest most confusing post this year . 

Morning  jermaine_rider

 

If it works with the pulley removed AND the timing cup is centered enough to not contact either HES pick-up, then possibly he might have magnetized the timing cup when he welded on it? (long shot but I suppose possible)

[jermaine_rider]

Same thing I was thinking. I'm pretty sure it's making contact somewhere. Something screwy is going on so I have a new pulley and timing cup on the way. That should tell me something when I put that on. I'll update you in about 5 days when the part shows up. Coming from Oregon. Thanks again.

[jermaine_rider]

Ok. First let me just say that in my world, nothing works out like I hope. That being said, the pulley came. I installed it . Hooked up the HES, got everything put back together except the plastics because they were sitting in the corner shining like Jack Nicholson from the wax job I gave in anticipation of finally riding my baby. Fired it up. NO. SPARK. Check all connections. Fuses. All the usual. Take the pulley off and the damn timing cup inside has come loose. Is it just me, or do those things NOT sit on the crankshaft perfectly even to where it doesnt contact the sensors? I put the two of them back on the crankshaft and it made a hideous noise when I cranked it so I pulled it off and went and bought some JB Weld. Waiting on it to cure now. In a few hours I will know what part I have to buy next because I just know this is not the end of my problems. Oh and the coils seem to be ok. Got no reading on primary using three different meters, but when I put 12v to one side and a test light to the other i get power to the test lite. If that is a conclusive test result then either its a motronic issue or a me issue. Any ideas?

[dirtrider]

12 hours ago, jermaine_rider said:

Ok. First let me just say that in my world, nothing works out like I hope. That being said, the pulley came. I installed it . Hooked up the HES, got everything put back together except the plastics because they were sitting in the corner shining like Jack Nicholson from the wax job I gave in anticipation of finally riding my baby. Fired it up. NO. SPARK. Check all connections. Fuses. All the usual. Take the pulley off and the damn timing cup inside has come loose. Is it just me, or do those things NOT sit on the crankshaft perfectly even to where it doesnt contact the sensors? I put the two of them back on the crankshaft and it made a hideous noise when I cranked it so I pulled it off and went and bought some JB Weld. Waiting on it to cure now. In a few hours I will know what part I have to buy next because I just know this is not the end of my problems. Oh and the coils seem to be ok. Got no reading on primary using three different meters, but when I put 12v to one side and a test light to the other i get power to the test lite. If that is a conclusive test result then either its a motronic issue or a me issue. Any ideas?

Morning jermaine_rider

 

The timing cup sits on the crankshaft little raised extension so it HAS TO center IF it is  correctly centered on that extension. Same with the pulley.  

 

I don't understand the coil resistance thing, IF it lights a 12v test light through the primary then it must have some sort of resistance reading. If it was open then the test light would not light & if it the primary was shorted then you would think that it should have a resistance (probably very low but a little anyhow). What scale was your meter on?

 

 

[jermaine_rider]

My meter has two settings for Reading ohms, 2000 and 200k. I have an analog that reads 4 ohms on the primary. I don't know about coils and resistance and 12v lighting up but what I do know is this bike is currently posted on marketplace for a stack. If somebody brings me a grand before I get the patience and money to tackle more issues then it's somebody else's HES nightmare. Here wrap your mind around this...the plug that the HES plugs into has 12v coming from all the wires except the ground wit key on. So how can the motronic read the signal coming from the HES when it is sending a signal out? What could cause that?

[dirtrider]

2 hours ago, jermaine_rider said:

The plug that the HES plugs into has 12v coming from all the wires except the ground with key on.  So how can the Motronic read the signal coming from the HES when it is sending a signal out? What could cause that?

Morning jermaine_rider

 

That is open circuit voltage as you have no load on the circuits.

[jermaine_rider]

Alright so new HES, pulley with the guts, coil is ok, new plugs, got fuel squirting from injectors, fuses and relays are good , what I have left unexplained is the red wire from the motronic to HES reads 12v to the connector, and no reading on the other side going to HES. I even removed the wire from both connectors and plugged it in by itself to make sure it was getting a good connection and I feel real dumb cuz I never seen a current just stop like that from one wire to the next so there's that and no spark . Oh and when I touch a ground wire to the motronic wires the fuel pump kicks on. That all I got. Might settle for $850 if this guy in Orlando will come get it in the next two days. Nothing ive read or seen online has come even close to the problems I have had. I just don't get it.

[dirtrider]

4 hours ago, jermaine_rider said:

Alright so new HES, pulley with the guts, coil is ok, new plugs, got fuel squirting from injectors, fuses and relays are good , what I have left unexplained is the red wire from the motronic to HES reads 12v to the connector, and no reading on the other side going to HES. I even removed the wire from both connectors and plugged it in by itself to make sure it was getting a good connection and I feel real dumb cuz I never seen a current just stop like that from one wire to the next so there's that and no spark . Oh and when I touch a ground wire to the motronic wires the fuel pump kicks on. That all I got. Might settle for $850 if this guy in Orlando will come get it in the next two days. Nothing ive read or seen online has come even close to the problems I have had. I just don't get it.

Afternoon jermaine_rider

 

Are you SURE the coil is good? That 4 ohm primary doesn't show a good coil (it should be between .5 & 1.0 ohms at room temperature but your meter accuracy is in question so who knows.

 

On the red wire losing 12v when plugged in, that 12v comes for the Motronic, so that power loss is probably due to the HES coils pulling that red wire circuit low when you connect the HES.  Try plugging the red wire back in but disconnect  the brown wire at the HES connector. See if it THEN shows 12v passing through to the HES. 

 

You REALLY need a known good HES as a quick test (that is what I use) or build yourself a simple HES tester (see the Personal Message that I sent you)

[dirtrider]

Afternoon jermaine_rider

 

With all the probing & testing/disconnecting remember that fooling with the HES (with the key ON)  on the 1100 can lock the Motronic out so do a number #5 fuse removal for a while before condemning the new timing cup/pulley. 

[jermaine_rider]

Got it. I'll check the message and see what I can do with the new info. Thanks again. What Jesse Jackson say? Keep hope alive!! Lol

[jermaine_rider]

OK not sure if it was this forum or another but I actually came across that diagram for testing the HES and posted it. Then I proceeded to replicate the testing procedure. Problem was, I left the HES plugged into the motronic and as you can imagine the results were NOT valid. So I ran the test again the right way and......the HES IS THE FATHER! (little Maury Povich humor. funny not funny) The HES did what it was supposed to do so that eliminates that suspect. Down to the coil and the brain. Gonna see why my primary reading on three different meters is coming back zero. Here is a pic of my tools and settings and how I use them in my pursuit of the illusive spark. I feel like an autobot from the planet Motronic battling for the element that gives life to our race, the AllSpark.  

[jermaine_rider]

so basically that is me testing a 7 ohm speaker to see what reading I get so that I know if my reading on the coil is correct using the analogue meter. Because my digital reads zero at the primary. Need to figure that out so I know which direction to go in.

[dirtrider]

Evening jermaine_rider

 

According to your digital you have a bad coil (open primary). According to your analog the resistance is too high (shorted primary).

 

What does your analog show with the leads hanging free (not connected)?  I see it has an ohm adjuster? Is that set to 0 with the leads hanging free?

[jermaine_rider]

The ohm adjuster was the reason for me testing the speaker , so I could have some way to calibrate it. I don't know how it works and rather not use it except for a back up. Odd though, that the coil would fail. But I guess anything is possible . I'm learning something new every day. Thanks for your help. 

[dirtrider]

3 hours ago, jermaine_rider said:

The ohm adjuster was the reason for me testing the speaker , so I could have some way to calibrate it. I don't know how it works and rather not use it except for a back up. Odd though, that the coil would fail. But I guess anything is possible . I'm learning something new every day. Thanks for your help. 

Morning jermaine_rider

 

There is definitely something strange going on as one meter shows an open, one meter shows 4 ohms (should be .5 - 1.0 ohms) , & the coil's primary passes 12v that lights a test light.  At least one of those is wrong. 

 

I don't know if your incandescent test light will respond quick enough (an LED will) but if you put it across the 2 wires going to the coil's primary (coil disconnected) then crank the engine, the test light should flash on & off as the HES  triggers the Motronic to fire the coil. 

 

You also sort of test the coil by putting a wire in each coil tower then rigging, them to be about 1/4" apart (spark gap). 

 

Then run 12v to the coils green wire terminal, then run a wire from the other coil primary terminal to near the 12v source. 

 

Then just scratch that wire on/across the battery negative post--- That should produce a spark across that secondary spark gap you made. 

[jermaine_rider]

Never heard that one before. Is there some diagram explaining that procedure ? I do better with visuals than texts. 

[dirtrider]

56 minutes ago, jermaine_rider said:

Never heard that one before. Is there some diagram explaining that procedure ? I do better with visuals than texts. 

Afternoon jermaine_rider

 

OK I will draw you one.

 

You can scratch the wire across the post or just tap it on & off. When the wire completes the circuit the coil charges (saturates) then when the wire breaks the circuit the coil secondary discharges across the spark gap.

 

[jermaine_rider]

ok I see the diagram.  pretty sure I can replicate it. So if I achieve spark between the gap in the secondary the coil is good right?

[dirtrider]

16 minutes ago, jermaine_rider said:

ok I see the diagram.  pretty sure I can replicate it. So if I achieve spark between the gap in the secondary the coil is good right?

Afternoon jermaine_rider

 

Probably good, at least it can make a spark. That looks like the old red coil & those can get some cracking in the case as they age. 

 

If you get a good ( bluish) spark in the above test then it should at least spark across a spark plug during an engine cranking spark test.   

 

On the cranking spark test be sure that the opposite side spark plug body is grounded to the engine case as your BMW uses a lost-spark type system so one coil sparks 2 spark plugs at the same time. Basically the spark comes out of one coil tower, passes through the first spark plug, travels through the engine case, then passes through the opposite side spark plug, then back to the other coil tower (sparks in a continuous loop). One side spark plug sparks positive center electrode & the other side sparks negative center electrode. 

[jermaine_rider]

Got ya. I need to have more definitive procedure because I am not looking forward to spending any more money at this time but if I have to I guess I have to.