Alpina Gremlins - guhhh

[cdnalpina]

So I have now a couple of gremlins with my 2 E34 Alpinas.

B10 Biturbo

I made a thread a little while back about how I had fuel delivery issues with the car. One day I go to start the car and it seems the fuel pump is dead. So I replaced the fuel pump with one from my parts car and the car runs but will not shut off after the key is out of the ignition. Tried a fuel pump relay swap and the car shut down normally... once.

Since then I went to my buddy's shop to try and trouble shoot it after work. I get there and have to stall out the car to make it stop running. He comes out and we set to go to work on it, starting with the connector to the fuel pump. What happens? 6 consecutive starts and shut downs as it should be. Not one run on after the key is removed. So I figure the gremlin must have moved on. Sadly, no - I get home from his shop and I have to stall it out again to turn it off. Any ideas here?

B10 3.5

The car runs really well (has a slight roughness to the idle but nothing severe). What happens with this car is the throttle will sometimes 'stick'. There is no rhyme or reason to it but it happens frequently. Sometimes at a light it will fluctuate between 1500 and 2000 rpm. Sometimes it will kick down to normal and other times it stays there for the duration of the light. While driving I can notice the same behaviour by virtue of the fuel economy needle. At speed, if you come off the throttle the needle should go to zero. In the B10, it will sometimes go to zero and other times it will be some value above that (indicating that it is still throttling). Last night when I got home, the car was idling high, so I quickly popped the hood and lsitened for when the motor stepped down and I did not see any movement in the throttle cable. So I am guessing that is not the root cause.

What I have done on the B10 3.5 so far is fuel filter, plug wires, cap and rotor. I have also changed the small vacuum lines and my Dad cleaned out the ICV. I am going to smoke test it tonight to see if there are any vacuum leaks.

Any suggestions or solutions to both problems would be greatly appreciated.

Cheers,

Rob

[ESSSupreme]

Don't really know but have you tried replacing main relay?

[uk525td]

:S lol i think that was the consensus in his previous thread

[CO535i]

On the B10 3.5 have you checked the throttle cable for binding? I mean if you are lucky enough to still have a throttle cable since some of those came with that drive by wire thing.

At your friends shop what did you do to the connector that gave you the good results when you were there? Seems the run-on is caused by the relay staying in an "on" state. I would begin with the grounds at the pump and the connections/terminals of the new pump to the in tank assembly.

I am not sure if Alpina used a separate pressure switched enrichment circuit for when the car is on boost giving you yet another thing to check.

[cdnalpina]

On the B10 3.5 have you checked the throttle cable for binding? I mean if you are lucky enough to still have a throttle cable since some of those came with that drive by wire thing.

At your friends shop what did you do to the connector that gave you the good results when you were there? Seems the run-on is caused by the relay staying in an "on" state. I would begin with the grounds at the pump and the connections/terminals of the new pump to the in tank assembly.

I am not sure if Alpina used a separate pressure switched enrichment circuit for when the car is on boost giving you yet another thing to check.

We are going to have a closer look at the B10 3.5 today. What we are going to do is see if we can recreate the high idle mcondition and if we can, shut the car down right away and then smoke it to see if the problem 'stays' when the car is shut down.

As for the Biturbo. I did try relays - all of them actually. So I fear it is some sort of electrical issue, like a short or something. The next test for the Biturbo will be to have the eboxes open and when the car does the run on, start pulling relays and see if any shut the car down and if so if it is instantaneous or if it takes a few seconds.

In the previous thread a few people suggested the ignition switch. What would be some common symptoms of one gone bad?

I'll get there eventually.

[CO535i]

In the previous thread a few people suggested the ignition switch. What would be some common symptoms of one gone bad?

I'll get there eventually.

Yep the ignition switch is completely plausible considering the age of the car. I had an 88 535i that did the same even after "switching off" the key. The instruments would shut down but one of the assorted idiot lights on the instrument cluster would remain on until the car was stalled out using the clutch.

[janders211]

Try taking off the tring around the ignition switch, so you can get at it with a hammer, or the end of a screw driver with a hammer.

When it is running (with the key out) try banging on the tumbler (not too hard) to see if it's a mechanical stick, and see if it shuts the car off. Also, while the trim is off try jiggling the wires and see if anything happens.

[cdnalpina]

Thanks guys - I'll give that a whirl. One other point of interest is that the car has the ASC and ABS lights on when I start up but as soon as I get going they go out. this happends everytime. I may get the car scanned as well and see if it yields anything.

[janders211]

I wonderif it is possible that you have some sort of short from something that is always 'hot' keeping the DME powered....I hate electrica problems- hopefully it's just a sticky ignition.


I remember in one (non-e34) car I owned the MAF wire was always hot, and it it shorted(i.e. pinched wires) - it would keep the car on.....also made them easy to steal.

[cdnalpina]

Alas, I am still plagued with my dual Alpina issues. Hoping for some more insgiht and suggestions. I do have some info to update with which may or may not help...

B10 Biturbo

Tried a myriad of things here. Replaced the fuel pump relays with 5 others to rule out the odds of having repeatedly bad relays - no luck. Tried Jander's suggestion with the ignition and no change. Changed the general module out from the B10 with no change. Swapped the DME relay with the B10 and no change.

Here's some interesting observations though. I replaced the fuel pump with the original one that was in the Biturbo originally (the one I thoguht was dead) and the car starts and runs fine with it in.

One key thing of interest is that the ASC and ABS lights are on when the car is started (as stated above). If I don't throttle the car to make the lights go out, I can shut off the car fine. I tested this about a dozen times and everytime it shut off. As soon as I throttle the car to make them go out, then the car runs on. I moved the car the other day only using reverse (was just rearranging cars on my driveway) and even though I was using the throttle in reverse, the ABS and ASC lights never went out and the car would shut off normally. I used my scan tool on the car and no codes (it's only an AST reader though).

So my suggestion is, could there be something buggered up with the DME? I'm going to check if the B10 3.5 has the same DME and try that. The crappy part is that the Biturbo has an extra controller that the boost line runs to - I certainly hope there is nothing wrong with that...


B10 3.5

So I thought I had the problem nailed with a sticking throttle cable and that is not the case. I have been driving the car for the last 3 days and here is what I observe:

- from cold the car always drives and throttles properly
- once warm the issue will come and go, even while driving (as stated above)
- coasting down a hill in gear with foot off the throttle, the car seems to be somewhat lost as to where the throttle should be, kind of hunts
- idle is rough and when it is doing its revving thing, there is almost a missing sound to the enxhaust

I am going to try and borrow my buddy's smoke machine to check for vacuum leaks but some other ideas I have are:

- despite cleaning the ICV, it may just be done and need replacing?
- AFM?
- accelerator potentiometer?

Car has new plug wires, cap and rotor - plugs were in great shape.


Any other ideas or suggestiuons of what to try first on the cars would be greatly appreciated.

Cheers,

Rob

[CO535i]

Thinking out loud-

B10 Biturbo-Throttle the car to get the revs up to increase the voltage from the alternator so that the lights shut off. Possible alternator field problem and or ground issue. Check your alternator brushes lately?

But, the only time I have had a run on issue with the key being turned to the zero position is that the plastic start switch under the key was faulty and would not shut off. Replaced it with a new ignition harness and the issue went away.

[Trevor M]

B10 3.5

The car runs really well (has a slight roughness to the idle but nothing severe). What happens with this car is the throttle will sometimes 'stick'. There is no rhyme or reason to it but it happens frequently. Sometimes at a light it will fluctuate between 1500 and 2000 rpm. Sometimes it will kick down to normal and other times it stays there for the duration of the light. While driving I can notice the same behaviour by virtue of the fuel economy needle. At speed, if you come off the throttle the needle should go to zero. In the B10, it will sometimes go to zero and other times it will be some value above that (indicating that it is still throttling). Last night when I got home, the car was idling high, so I quickly popped the hood and lsitened for when the motor stepped down and I did not see any movement in the throttle cable. So I am guessing that is not the root cause.

What I have done on the B10 3.5 so far is fuel filter, plug wires, cap and rotor. I have also changed the small vacuum lines and my Dad cleaned out the ICV. I am going to smoke test it tonight to see if there are any vacuum leaks.

Any suggestions or solutions to both problems would be greatly appreciated.

Cheers,

Rob


I think your clue here is the fuel economy gauge. If the RPMs are above 1700 (I think), the throttle is closed and you are in decel, the gauge should always read zero. If the throttle switch is bad, this would confuse the DME into thinking you are accelerating when you're not and will adjust firing of injectors accordingly. This would mess with the O2 sensor and it's feedback loop which in turn would cause the car to run funky. Check the throttle switch and check to ensure the butterfly valve in the throttle body isn't sticking whats so ever.

Too bad we weren't living closer, I have a M30B35 in a parts car we could swap things from to try and isolate it.

[cdnalpina]

Thinking out loud-

B10 Biturbo-Throttle the car to get the revs up to increase the voltage from the alternator so that the lights shut off. Possible alternator field problem and or ground issue. Check your alternator brushes lately?

But, the only time I have had a run on issue with the key being turned to the zero position is that the plastic start switch under the key was faulty and would not shut off. Replaced it with a new ignition harness and the issue went away.

So if I had a weak alternator would that cause the ASC and the ABS lights to omce on? Interesting idea for sure and will have to check that out. I'll put a volt meter on the battery when it is running and see what voltage is being put out. Thanks for the idea! I am also going to pull the ignition switch form my parts car and have it handy to try swapping in where other ideas fail, provided it didn't get caught up in the fire that killed the car (had an electrical fire behind the dash that went down to the knee bolter).


I think your clue here is the fuel economy gauge. If the RPMs are above 1700 (I think), the throttle is closed and you are in decel, the gauge should always read zero. If the throttle switch is bad, this would confuse the DME into thinking you are accelerating when you're not and will adjust firing of injectors accordingly. This would mess with the O2 sensor and it's feedback loop which in turn would cause the car to run funky. Check the throttle switch and check to ensure the butterfly valve in the throttle body isn't sticking whats so ever.

Too bad we weren't living closer, I have a M30B35 in a parts car we could swap things from to try and isolate it.

So when you say throttle switch, is that the pedal potentiometer or is it something else? I have a parts car (m30B35) so I can pilfer from it for sure. If you could give me some more direction with this idea I would greatly appreciate it!

Indeed shame you are not closer, would be nice to have someone else to wrench with more than anything else :)

[Trevor M]

So when you say throttle switch, is that the pedal potentiometer or is it something else? I have a parts car (m30B35) so I can pilfer from it for sure. If you could give me some more direction with this idea I would greatly appreciate it!

Indeed shame you are not closer, would be nice to have someone else to wrench with more than anything else :)

I'm assuming on your B10 the throttle is set up by a cable and not a electrical servo, correct? I don't know what year this car is.
As far as I know, on Motronic 1.3 there is no potentiometer, just a switch. It's connected to the same shaft the butterfly valve is on. It has two switches and only one of three possible states.
First is throttle closed - the Idle switch will be closed and have continuity, the WOT switch is open.
Second is part throttle - both switches are open
Third is wide open throttle - The WOT switch will be closed, idle open.

It's possible the switch could be bad or out of adjustment (idle switch never closes)

[cdnalpina]

The B10 is a drive by wire - I'd assume it is the same as yours? Mine's a late 90 build. I'll look into that tomorrow with my buddy and see what he can discern from your ideas. Many thanks for that input!

Interestingly, Alpina installed a throttle body similar to that of an E31 on the Biturbo.

Here's a shot of the engine bay and you can see the throttle body therein:

http://mydrive.roadfly.com/photos/pic.php?u=132941UQjJM&i=13268

Here's what the throttle body looks like compared to that of an E31, BT throttle body is on the left in this picture

http://mydrive.roadfly.com/photos/pic.php?u=132941UQjJM&i=8884

And on top in this picture

http://mydrive.roadfly.com/photos/pic.php?u=132941UQjJM&i=8885

On my Biturbo, my buddy is convinced it is still the ignition switch (mechanic). I'm going to pull the one from my parts car and try it tomorrow (no guarantee it is good of course, but worth a shot). Running out of days to drive the BT and man oh man do I miss driving it...

[attack eagle]

Easy way to determine if it is the ignition switch... unplug the SOB down behind the bolster when it is running on with the key off. If it shuts down, key switch is bad.

If not then you have an electrical gremlin elsewhere.

Thinking aloud:

Check the alternator fuse also. I blew one doing a turbo swap on my DSM and the car wouldn't shut off.

A bad engine ground could possibly cause a similar issue. That's easy enough to test. Use a spare piece of wire to ground the engine when it is running on.

Good luck brother!

[motohunter4]

check your alternator voltage. mine was putting out 12.9v and i had all kinds of electrical gremlins, swapped it out for another one that put out 13.9v and no more issues.

[M Quick]

If you get bad voltage that may cause all sorts of electrical problems really. So check the ground cables engine to chassis etc and also meassure up the alternator. Sounds like the alternator isn't giving enough juice and is causing problems. Also check the health of the battery.

Oh, forgot to add, the alternator should put out anything from 13.8v to 14.4v if healthy. The battery (if fully charged) 12.72v but around 12.5v is usually fine too.

[cdnalpina]

Easy way to determine if it is the ignition switch... unplug the SOB down behind the bolster when it is running on with the key off. If it shuts down, key switch is bad.

If not then you have an electrical gremlin elsewhere.

Thinking aloud:

Check the alternator fuse also. I blew one doing a turbo swap on my DSM and the car wouldn't shut off.

A bad engine ground could possibly cause a similar issue. That's easy enough to test. Use a spare piece of wire to ground the engine when it is running on.

Good luck brother!

Great suggestions, thank you! I'll give that a spin tonight after I pull off the ignition switch and alternator form the parts car - might as well have both handy. Good call on the alternator fuse, will check that as well.


Seems there is a big push for the charging system so I will throw a volt meter across the battery with the car off and running and see what it reads. Will be interesting to see if it is any different when the car is 'running on' versus just running normally.

[5senses]

Just read this thread and there are too many suggestions followed by attempts.. I feel your pain of not driving but the attempts rule out each possibility 1 by 1..
If its the alternator have yours rebuilt.. current alternators on the market have a lower amp than whats needed on your car(s).. hopefully the 1 from your parts car is workable.. If its not the alternator then keep diagnosing until its solved..

Good luck

Wes

[woods]

Sounds like you're on track with the B10 problem. For issues like this, I often start pulling any connector I can get my hands on that might be related to the problem, and check and clean all of the contacts. I have witnessed the replacement of DMEs on several occasions when a simple cleaning of the contacts was all that was needed. Could be a short somewhere too... Ugh.

The B35 problem sounds exactly like a problem I used to have on my E36. I was sure it was the ICV but turned out to be a leak in the intake via the crank case breather. Once the car warmed up, the valve cover would expand enough that the old and flat o-ring on the crankcase breather would start leaking, drawing unmetered air right into the intake. Had similar issues with my s38 due to cracks in the intake bellows. With a small intake leak, the car can idle OK when cold because the DME is already over-fuelling slightly during the startup cycle. This will compensate for additional air.

[cdnalpina]

Just read this thread and there are too many suggestions followed by attempts.. I feel your pain of not driving but the attempts rule out each possibility 1 by 1..
If its the alternator have yours rebuilt.. current alternators on the market have a lower amp than whats needed on your car(s).. hopefully the 1 from your parts car is workable.. If its not the alternator then keep diagnosing until its solved..

Good luck

Wes

Thanks Wes. It is a frustrating situation but I know I will get there eventually. I just greatly appreciate all the help and suggestions from everyone - make figuring out what I should look at next a whole lot easier. At least I am eliminating things one by one and hopefully narrowing down on the problem...


Sounds like you're on track with the B10 problem. For issues like this, I often start pulling any connector I can get my hands on that might be related to the problem, and check and clean all of the contacts. I have witnessed the replacement of DMEs on several occasions when a simple cleaning of the contacts was all that was needed. Could be a short somewhere too... Ugh.

The B35 problem sounds exactly like a problem I used to have on my E36. I was sure it was the ICV but turned out to be a leak in the intake via the crank case breather. Once the car warmed up, the valve cover would expand enough that the old and flat o-ring on the crankcase breather would start leaking, drawing unmetered air right into the intake. Had similar issues with my s38 due to cracks in the intake bellows. With a small intake leak, the car can idle OK when cold because the DME is already over-fuelling slightly during the startup cycle. This will compensate for additional air.

Could not agree more - I have solved many problems by reseating relays and fuses. will definintely try the easier things like that first :)

[cdnalpina]

UPDATE!

Well I decided to change all the fuses to the newer type in the fuse box and low and behold, the ABS and ASC lights don't come on anymore! Checked the voltage on the car when running and it is a steady 13.87V - which I assume is borderline ok?

I haven't tried Richard's suggestion about the harness because in truth I was a little confused where to look and unplug. Could someone give me some guidance on that please?

I haven't had much time to play with the B10 3.5. I pulled the connector on the throttle body and reseated it to see if that helped - nope. I think I really need to smoke test the car, feels like an uber bad vac leak plus something else. TBA...

[gfycorp]

UPDATE!

Well I decided to change all the fuses to the newer type in the fuse box and low and behold, the ABS and ASC lights don't come on anymore! Checked the voltage on the car when running and it is a steady 13.87V - which I assume is borderline ok?

I haven't tried Richard's suggestion about the harness because in truth I was a little confused where to look and unplug. Could someone give me some guidance on that please?

I haven't had much time to play with the B10 3.5. I pulled the connector on the throttle body and reseated it to see if that helped - nope. I think I really need to smoke test the car, feels like an uber bad vac leak plus something else. TBA...

B10

My crappy Ford Ranger work truck had the same idle issue from what it sounds like, except a bit worse. It would idle up to about 3500 randomly until at a complete stop, and then it would idle regularly. If you pulled it out of gear or let off the gas it would try and go back to 3500RPM too.

Checked the cable, cleaned, lubed it. Didn't help. Cleaned the horridly corroded battery terminals and it went away. Go figure.

Then on my 535i with the same Fly-By-Wire I had the same-ish issue. It would idle up to like 1800 then hunt around from 400-1800 at a stop. One of two things fixed my problem:

I took a giant can of MAF cleaner to the throttle body and VAF to get all the carbon and gunk off it and cleaned my Crank Position Sensor that, due to an awful oil leak, was covered in oily gunk to the point where there was no gap between the CPS and the teeth it was trying to read.

Not sure which fixed my problem as I did them at the same time, but I will say that my throttle body flapper was getting stuck when moved by hand due to the accumulated crap all over it, but once clean it moved freely.


Might start there; can't hurt since nothing else seems to be working.

Biturbo:

Does your ignition feel notchy at all when you turn the key? Or different than it did before when going Off -> Start or vice versa? Looser? Harder to get moving but still turns with enough force? The same as before?

[Binjammin]

:rofl I don't think it can be called idling when you're at 3500rpm! I've seen a lot of cars that will hunt idle like that end up having a bad coolant temp sensor. Not sure the same behavior applies to a bmw though, but it wouldn't surprise me.

[cdnalpina]

Thanks for the feedback and ideas.

On the B10 I have cleaned the ICV and emptied an entire can of brake clean, cleanig out the throttle body to no avail. I'll check the crank position sensor - haven't tried that yet. I have a spare AFM and throttle body from a parts car - I may try switching those out and seeing if there is any improvement. Agreed that doing these things can not hurt for sure.

On the Biturbo, the key really feels no different than before the problem - or if it is different, the change is so subtle that it was notable for me. Drove the car last night and enjoyed the hell out of taking it for a run and stretching its legs. Just kind of embarassing to have to stall it out to shut it off when I get home. I think I will next focus on the ignition switch - it all seems to be pointing in that direction or an electrical gremlin somewhere. Hopefully it is just the switch...


:rofl I don't think it can be called idling when you're at 3500rpm! I've seen a lot of cars that will hunt idle like that end up having a bad coolant temp sensor. Not sure the same behavior applies to a bmw though, but it wouldn't surprise me.

I have seen failed coolant temp sensors on and E32 V12 and it caused the car to run stupid rich but not hunt around. Car thought it was always -40C.

That said, this is an inline 6 so a different beast. My buddy has a scan tool that can see what the sensors are reading for values - worth seeing if something like that is totally out of wack for sure. Good suggestion!

[bolloc]

Thanks for the feedback and ideas.

On the B10 I have cleaned the ICV and emptied an entire can of brake clean, cleanig out the throttle body to no avail. I'll check the crank position sensor - haven't tried that yet. I have a spare AFM and throttle body from a parts car - I may try switching those out and seeing if there is any improvement. Agreed that doing these things can not hurt for sure.

On the Biturbo, the key really feels no different than before the problem - or if it is different, the change is so subtle that it was notable for me. Drove the car last night and enjoyed the hell out of taking it for a run and stretching its legs. Just kind of embarassing to have to stall it out to shut it off when I get home. I think I will next focus on the ignition switch - it all seems to be pointing in that direction or an electrical gremlin somewhere. Hopefully it is just the switch...

Sorry I don't recall what was in other threads about this car, so I am just going to ask anyway, did someone install an aftermarket remote starter? Or for that matter, an alarm, keyless entry, stereo?




I have seen failed coolant temp sensors on and E32 V12 and it caused the car to run stupid rich but not hunt around. Car thought it was always -40C.

I thought that the outside temp sensor value was only used for the obc display, did I assume wrong?

[cdnalpina]

Sorry I don't recall what was in other threads about this car, so I am just going to ask anyway, did someone install an aftermarket remote starter? Or for that matter, an alarm, keyless entry, stereo?




I thought that the outside temp sensor value was only used for the obc display, did I assume wrong?

Good suggestion but no aftermarket alarm or anything. The only thing is an aftermarket park distance control setup. I doubt it would affect anything but I will look into it though.


The temperature sensor we are referring to is the coolant sensor. In the case of my buddy's E32, the car thought the block was always at -40C, based on the coolant temperature that was sent to the computer. So the car ran rich all the time thinking it needed to warm itself up.

[bolloc]

Good suggestion but no aftermarket alarm or anything. The only thing is an aftermarket park distance control setup. I doubt it would affect anything but I will look into it though.

The radio? Its amazing how people screw these things up... reason I am suggesting these things is most people have already mentioned the logical stuff and you appear to have tried most of it, got me to thinking its going to be one of those off the wall things.



The temperature sensor we are referring to is the coolant sensor. In the case of my buddy's E32, the car thought the block was always at -40C, based on the coolant temperature that was sent to the computer. So the car ran rich all the time thinking it needed to warm itself up.

Oh ok....

[Racerhoze]

For the one that randomly idles high... have you checked the throttle position switch?