Need to purge Fuel Injection after Filter Change ?

[Great White North]

I have a new-to-me '06 R1100RT, just carried out my first fuel filter change. I am not new to mechanical maintenance, but I am new to this whole BMW world.

 

I have a few questions:

 

1. Is there a need to purge the Fuel Injection system for air bubbles after filter change? The bike has yet to run steadily after this job, and I tried quite a few times. It will 'sometime' start, but only runs for 5-10 seconds...

 

When I turn the ignition on, I can hear the fuel pump starting up, then stopping (as per normal), but then the pump sometimes starts again (before engine starts) and I hear what sounds like a scratching noise coming from the throttle body of left side. (I know, I know, the gremlins are trying to scratch their way out... :-)

 

Anyways, I did disconnect the fuel lines at each injector and turn on the ignition to ensure fuel was coming out, no probleme there.

 

Any help with this would be greatly appreciated.

 

Thanks !

[Ken H.]

Is this an '06 R1200RT or an older R1100RT? I'm confused because there is no user replaceable fuel filter on an R1200RT and the R1100RT was discontinued in 2001.

 

There is no purge needed, or even possible.

 

During the 5-10 seconds that it does run, does it run/idle normal?

[Great White North]

Sorry folks, the RT is '96 (they should not put that 0 and 9 so close together on that keyboard... :-)

 

To answer your question, During the run time, the engine only runs if I keep the throttle slightly open, it will not idle on its own.

 

Also, It does not start on first attempt neither, unless I turn the ignition on/off a few times first - can't explain that one. I will take the tank / pump apart again this evening to ensure all is hooked up properly, and nothing is binding inside the tank.

 

M.

[Great White North]

... AND I now realize I was in a different thread reading up on other postings when I posted this item, (Rookie's mistake !)

 

Sorry, will post this item over to the OILHEADS forum..

 

What a way to make my arrival into this forum community :-)

 

Sorry folks.

 

M.

[smiller]

To answer your question, During the run time, the engine only runs if I keep the throttle slightly open, it will not idle on its own.

Check that the throttle cables are fully seated at both throttle bodies. Having the ferrule of one cable or the other not fully seated is a very common cause of the symptoms you describe.

[Great White North]

<<< This is a repost in Oilheads Forum - Had Posted initially by mistake in Hexheads forum >>>

 

I have a new-to-me '96 R1100RT, just carried out my first fuel filter change. I am not new to mechanical maintenance, but I am new to this whole BMW world (and this forum).

 

I have a few questions:

 

1. Is there a need to purge the Fuel Injection system for air bubbles after filter change? The bike has yet to run steadily after this job, and I tried quite a number of times. It will 'sometime' start, but only runs for 5-10 seconds, IF I keep the throttle slightly open - It will not idle on its own.

 

When I turn the ignition on, I can hear the fuel pump starting up, then stopping (as per normal), but then the pump sometimes starts again (before engine starts) and I hear what sounds like a scratchy noise coming from around the throttle body on left side. (I know, I know, the gremlins are trying to scratch their way out... :-)

 

Anyways, I did disconnect the fuel lines at each injector and turn on the ignition to ensure fuel was coming out, no probleme there.

 

Any help with this would be greatly appreciated.

 

Thanks !

[Great White North]

Good suggestion! (I remember the RH side coming out when I was removing the fuel lines to remove the tank) I just checked and the cables were both seated properly.

 

Thanks.

 

 

[Twisties]

... AND I now realize I was in a different thread reading up on other postings when I posted this item, (Rookie's mistake !)

 

Sorry, will post this item over to the OILHEADS forum..

 

What a way to make my arrival into this forum community :-)

 

Sorry folks.

 

M.

 

Welcome to the board! Take a look at the UnRally forum. It's our annual gathering and is held in a different location each year. This year it happens to be in your backyard I think.

[Great White North]

Thanks for heads up on rally. It is about 8 hrs drive from here, I have gone camping with family in that area for the past 3 summers. Great riding area I'm sure (wish I had my bike, but had to tow camping trailer instead...) The kangamangus highway is very scenic and runs between Lincoln and Conway NH. Most of the highway runs along the Saco river I believe. The white mountains area as a whole is scenic. Would be even better during the fall foliage season, but it is a great summer spot.

 

Cheers,

 

m.

 

 

[Satguy]

well, did you get it going??

 

Is is possible that you reversed the fuel lines from the tank to the regulator?? Regulator is the part attached to the plastic fuel lines and sits behind the engine and in front of the air box.

 

One is supply (pressure) and the other line is the return to the tank (no pressure)

 

I can't remember what the symptom would be if the lines are reversed, but if my memory is correct it will not run well.

 

[Great White North]

Still No Go, I had labled the fuel lines before removing tank, so I 'think' they are back on properly, but it never hurts to double check. I did check that fuel was coming out of each fuel line to the injectors when the pump runs.

 

Something to check tomorrow.

 

Thanks !

[John844]

I would start by ensuring that the throttle cables are fully seated on each throttle body. If one of them is out of place, it causes the same symptoms you are having.

 

I did not have to do any bleeding/purging the last 2 times I changed mine, and I don't rember reading anything about that.

[Great White North]

I checked the throttle cables, and both were seated properly. Sounds like bleeding/purging for air in the Fuel system is not a necessity.

 

Is there a procedure for cleaning injectors, perhaps they got fouled up by something disloged in fuel system - this bike had been parked for a couple of years before I bought it not long ago. Bike ran fine until replacement of filter.

 

Removing Tank again tomorrow to double check that all is good inside...

 

Thanks again,

 

m.

[taosports]

The fuel filter is directional...did you note that when installing?

[Joe Frickin' Friday]

When I turn the ignition on, I can hear the fuel pump starting up, then stopping (as per normal), but then the pump sometimes starts again (before engine starts) and I hear what sounds like a scratchy noise coming from around the throttle body on left side. (I know, I know, the gremlins are trying to scratch their way out... :-)

 

This is an interesting symptom. Have you double-checked the electrical connector at the fuel tank?

 

If you're sure this connector is firmly seated, then one other long-shot suspect, to me at least, is the HES. It would be a really weird coincidence if this were malfunctioning right now, but your symptom - fuel pump triggering at odd time, left TB noise - kind of sound like it. When the HES malfunctions so that the signal "floats" right around the transition point (rather than pegging at 11 or 1 volts), the Motronic sometimes interprets that fluttering signal as a real pulse train from the HES, and so it triggers the fuel pump to run for another cycle, and fires the injectors and spark plugs. The "scratchy" noise you hear the left TB (if the HES is dying) would be the fuel injector firing at a really irregular rate. You would expect this at both TB's.

 

One other symptom that would point to HES failure: a fluttering tachometer needle in conjunction with that "scratchy" TB noise, even when the engine isn't being run.

 

How many miles on the bike? Is this the original HES? It's possible you jostled the HES wiring when you were removing/installing the tank, and the old, crappy insulation cracked to pieces and shorted something.

 

Let us know what the tach is doing...

[boatzo]

The fuel filter is directional...did you note that when installing?

 

+1 on the filter direction. Also check that the 2 hoses from the tank are connected correctly. One is supply and one is return.

[Great White North]

Good suggestion re: filter direction, I did check it this evenign , and all plumbing inside the tank, that was OK.

 

Tank electrical connection seems OK, fuel gauge Reads normal, fuel pump works.

 

Beats me... fuel lines were double checked. There is pressure at the injectors.

 

 

[Great White North]

 

This is an interesting symptom. Have you double-checked the electrical connector at the fuel tank?

 

Yes, tank connector was double checked, cleaned with electronics cleaner - all seems good.

 

If you're sure this connector is firmly seated, then one other long-shot suspect, to me at least, is the HES. It would be a really weird coincidence if this were malfunctioning right now, but your symptom - fuel pump triggering at odd time, left TB noise - kind of sound like it. When the HES malfunctions so that the signal "floats" right around the transition point (rather than pegging at 11 or 1 volts), the Motronic sometimes interprets that fluttering signal as a real pulse train from the HES, and so it triggers the fuel pump to run for another cycle, and fires the injectors and spark plugs. The "scratchy" noise you hear the left TB (if the HES is dying) would be the fuel injector firing at a really irregular rate. You would expect this at both TB's.

 

HES was removed and tested (according to procedure by Dana Hager). Both upper and lower sensors tested OK, and were fine under some heat treatment.

 

Glad I got in there, the alternator belt was in shreads... new one is now in place.

 

One other symptom that would point to HES failure: a fluttering tachometer needle in conjunction with that "scratchy" TB noise, even when the engine isn't being run.

 

Tach is steady, and since double checking filter and reinstalling tank, 'scratchy' is gone...

 

How many miles on the bike? Is this the original HES? It's possible you jostled the HES wiring when you were removing/installing the tank, and the old, crappy insulation cracked to pieces and shorted something.

 

Bike odometer reads 49000 km's - but I'm not sure if this is the original tach/odometer...

As to if the HES is original, again, not sure but it is an OEM part number on it - the wiring at both ends of the HES is actually in pretty good condition - I had read that this wiring has a tendency to succomb to heat / vibrations... I cleaned all parts while the HES was out - no sigh of aging insulation (may point to it being replaced at one point in time).

 

How can I go about testing the plugs and coil ? I don't seem to be getting any spark on the plugs (when tested with a ground on the body of the plug) - Should I see a spark, or it the firing of the plugs controlled by the electronic module ?

 

Same thing with Injectors, how can I test that these are working ok ? I removed the fuel line on each, and there is fuel pressure at the injectors.

 

To Forum: All your help is much appreciated, I've learned a LOT about this bike in the past couple of days, and have caught a couple of problems just waiting to happen... !

 

 

[Great White North]

Double checked lines, they 'seem' ok, but now wondering if I mislabeled the lines. Is the top one going into regulator the feed, and bottom one return ?

[Satguy]

OK, Need more information.....It sounds like this bike is new to you and has not run in some time??

 

If it ran OK just prior to the fuel filter change, there has to be something simple that was put back or connected incorrectly during the fuel filter change. If the bike has never run while in your posession, then it could have any number of faults/problems from previous attempts to make it run.

 

Yes, there should be spark with the plug grounded during cranking. Side stand must be up and bike in neutral.

 

You can check the injectors by simply pulling one out of the throttle body and cranking the engine over. See if you get "puffs" of fuel mist, it should be obvious that they are working or not. If bike has been sitting for a long period of time injectors can become fouled and not spray at all or incorrectly. I have seen this on a brand new bike that sat in the warehouse for 2 years, it would not start until new injectors were installed.

[Great White North]

Need more information.....It sounds like this bike is new to you and has not run in some time??

Bike has run fine prior, I've put about 2k km's on it since purchase. I had a 'rain' incident just prior to this happening, where bike died in rain storm. Trailer'ed it home started fine once here. Then decided to investigate condition of HES and other possible cause of malfunction in rain, in retrospect, bad decision.. !!

 

Yes, there should be spark with the plug grounded during cranking. Side stand must be up and bike in neutral.

You can check the injectors by simply pulling one out of the throttle body and cranking the engine over. See if you get "puffs" of fuel mist, it should be obvious that they are working or not.

 

OK, so I checked for spark (stand up, neutral, plug casing grounded), nothing. I did pull RH side injector, no sign of fuel puffs, but there is pressure at the injector, Injector not opening up by the looks of it, so I suspect something in the control unit gone bad somehow...

 

Is there a way to identify if control unit is fried, or putting out error codes ?? Nearest dealer is 2 hrs away - so keeping that option as last resort...

 

Thanks for your help.

 

Cheers,

 

M.

[Boffin]

I would bet money on this being a HES issue. I know you have tested them but there have been several cases of HES' testing fine but not working on the bike. I suggest pulling the HES and removing the cable sheath. I bet the inner insulation has crumbled.

The motronic pulses the injectors bases on HES signals.

 

Andy

[boatzo]

Try going back over all the electrical connections that you can see and see if any are pulled loose or not seated. Check the fuse panel for blown fuses. I believe fuse #5 is the motronic.

[smiller]

I would bet money on this being a HES issue. I know you have tested them but there have been several cases of HES' testing fine but not working on the bike. I suggest pulling the HES and removing the cable sheath. I bet the inner insulation has crumbled.

The motronic pulses the injectors bases on HES signals.

The HES certainly is a possibility for the reasons that Mitch and Andy describe. If you see a flaky tach needle that would be a dead giveaway.

 

Given that you have an early 1100 it's probably a good idea to proactively replace the HES harness wiring since this is such a common failure item. Even if that isn't the problem in this case the work needs to be done anyway, and if it is the problem, well, that's even better.

 

Here is a tutorial on replacing the HES harness. Note that you will probably only have to replace the harness wiring and not the sensors themselves as the latter have a very low failure rate. The required PTFE/Teflon wire can be obtained from any number of sources.

 

[Satguy]

Yep, definately the motronic is not being told to fire the spark plugs or activate the injectors.

 

You need to check the hall sensor next..... You said that the alternator belt was shredded,yes?

 

I would take off the alternator pulley to allow a visual inspection of the hall sensor and the trigger plate (disc). I have seen a shredded alternator belt damage the hall sensor and the trigger disc when strands of the belt wrapped around the hall sensor. The bike then will not run.

 

I have never seen a motronic computer go bad on one of these bikes. Not to say that it can't happen, but rare none the less.

[Joe Frickin' Friday]

Bike has run fine prior, I've put about 2k km's on it since purchase. I had a 'rain' incident just prior to this happening, where bike died in rain storm. Trailer'ed it home started fine once here. Then decided to investigate condition of HES and other possible cause of malfunction in rain, in retrospect, bad decision.. !!

 

OK, so I checked for spark (stand up, neutral, plug casing grounded), nothing. I did pull RH side injector, no sign of fuel puffs, but there is pressure at the injector, Injector not opening up by the looks of it, so I suspect something in the control unit gone bad somehow...

 

OK, so your bike previous crapped out in wet weather, started fine shortly after. And very recently your fuel pump was cycling at odd times, and you were getting a "scratchy noise" at one of the throttle bodies. And now you're not getting any spark or fuel injection at all.

 

These are all classic HES failure symptoms. As Seth noted, usually the sensors themselves are fine but the insulation inside the harness cracks to pieces and allows a short when moisture works its way in.

 

You can test the HES on the bike. Key on, jam your DVM probes into the back of the connector. See here for a wiring schematic. With the key on and sidestand up, slowly roll the engine through a revolution or two (use a wrench on the alt belt pulley, or put the bike in fifth gear and bump the back wheel; engine spins clockwise when viewed from front), and watch for the signal to transition smartly between (IIRC) 1 and 11 volts. Signals should not be fluttering somewhere in between, and should not slowly transition between high and low. If it's working well, it shouldn't be hard to identify the transition; the gate width is, IIRC, something like 30 crank-angle degrees.

 

Bruce might be right about alt belt debris screwing up the physical operation of the HES and gate cup. But if you've got all the chunks outta there and the bike still won't fire, it's probably the HES wiring. If you've got soldering/wiring skills, I'd strongly suggest rewiring with teflon-insulated wire. If not, pick up a new HES, and all should be fine.

[Great White North]

OK, next step is to test HES on bike, will post results !!

 

Thanks again all.

[philbytx]

A new HES can be had (and sent to you fairly quickly!) from John at EURO MOTO ELECTRICS

 

I (and some others on the board) used him for my HES replacement plus a new starter. He is a great guy to deal with and is very prompt with his service.

[Great White North]

Ahhh Ha ! I think we have a culprit.. Tested HES at connector, here's what I'm reading.

 

Input voltage: 11.9V

 

Upper sensor range (Orange) 1.1V - 0.7V

Lower sensor range (Black) 3.3V - 0.5V

 

I now realize that the test procedure I used, (using a LED and resistor in series to test output), would show voltage and current passing, but even at a low voltage, the led would light up... ANOTHER good lesson learned.

 

So, sounds like I'm shopping for a HES...

 

Arghhhhhhh... another week without the bike !!

 

Thanks all.

 

M.

[boatzo]

Try re-doing the wiring to the hes as Mitch suggests. You may save the cost of new HES and get on the road quicker.