E34 M5 stalling

[SS540i]

I recently bought a 94 euro m5 and have encountered a little problem. The car runs and drives perfect and then recently it intermittenly shuts off on its own. What happens exactly is that it will start, then after you drive it for a couple minutes, it just shuts off. It will not start back up right away but after a few tries it will start and run fine for the whole day. It just does it in the beginning of start ups. I switched the following parts already from another m5 to see it would fix the problem, but nothing has changed: fuel pump, fuel pump relay, new fuel filter. The fault code A1 came up on the peake scanner which I believe means control unit supply. Any help is greatly appreciated.

[PorscheH6]

Could be a faulty MAF.

Pics of M5? You're lucky to have such a rare beast here in the 'States.

[SS540i]

Will check that but I dont think that is the problem. If you look at threads I started, I put some pics of it on here

[TGreene]

You might want to check the fuel pressure at the injector rail to be sure, but maybe you also want to check the crank position sensor and cam position sensor?

[SS540i]

I was thinking it could be the crank sensor about to go out because I know that can cause the engine to shut off. That is gunna be my next move. I will post results

[91e34M5]

Do you have coil packs or an individual coil? If you have an individual coil...check it. They can do weird things like you describe when they go bad.

[SS540i]

This motor has individual coil packs. Yea you are right, the single coil can do weird things. But, unfortunately mine is a bit different.

[NikosX]

Crank sensor.

[speedracer08]

Pictures of the car..... another vote for the crank position sensor sometimes called a pulse generator.

[janders211]

Could be a variety of shorts. I would try cleaning every connector and ground you can find and putting a small amount of dielectric grease on each connection.

Also try swapping DME's if you have one available.

[SS540i]

I changed out the crank sensor and the same thing is happening. It seems to only do it after I shut the car off and turn it back on when it is warmed up a bit.

[93FIM5]

Could be a variety of shorts. I would try cleaning every connector and ground you can find and putting a small amount of dielectric grease on each connection.

Also try swapping DME's if you have one available.

Good input, also check the fuel pump relay and the engine control relay with known good units and the fuseable link. Ive had relays be kinda finicky before thats why I suggest swapping them with new ones its cheap insurance and keep the others as spares for in a pinch if you want.

[Elekta]

I had same issue and it was a hairline crack on a $.25 fuse

Check the cheapest stuff first :cool

[SS540i]

Which fuse was bad on yours? I checked them all and seem to be ok

Im almost sure it is something electrical because when you kill the fuel pump when the car is on, it studders for a bit until the fuel pressure is gone and then shuts off. But, the way it is happening is that it just dies right away, no studder or anything. Are there any places that you guys know of that can check dme units for any problems?

[fronton]

If it were a faulty MAF, wouldn't is just run in limp mode? Sounds like an electrical issue to me. Check for lose grounds, ECU, battery. Does it ever die when hitting a bump or just cruising along at 65 on a smooth road whenever totally out of the blue?

[PorscheH6]

Bad MAF can cause a stall, given the right circumstances. At least that's my exp. on the 3.6

[SS540i]

When it dies, I am usually sitting at a light or right when I put it in second gear and cruising normally. It doesnt happen when the engine is cold, only when its warmed up it. Bumps really do not change the circumstances. Is the only main ground wire the one on the passanger side motor mount bracket? I am going to clean all of the ground wires, but everything seemed ok and tight. Could it be the ignition switch perhaps?

[ss109]

It sounds like a fuel issue, but you've already covered all the bases.

I also had a situation similar to Elekta's - I also had a faulty fuse that appeared fine but would cause intermittent problems.

Sorry I am of no more help.

[Elekta]

Which fuse was bad on yours? I checked them all and seem to be ok

Im almost sure it is something electrical because when you kill the fuel pump when the car is on, it studders for a bit until the fuel pressure is gone and then shuts off. But, the way it is happening is that it just dies right away, no studder or anything. Are there any places that you guys know of that can check dme units for any problems?

I can't remember but I bought a paddle fuse tester and pulled everyone and put them in the tester and wiggled it around and the green light went red so I chucked it and the fuel issue disappeared just like that. There was the slightest hairline crack in it too.

[jint45]

You might want to check the fuel pressure at the injector rail to be sure, but maybe you also want to check the crank position sensor and cam position sensor?

S38's have a cam position sensor??? i can't find one on my engine, where is it?

[Grim Reaper]

S38's have a cam position sensor??? i can't find one on my engine, where is it?

Part 12 on this diagram for my 3.8 M5

http://www.realoem.com/bmw/showparts.do?model=HC91&mospid=47387&btnr=11_1260&hg=11&fg=15

[SpeedsterBek]

Not familiar with S38 but if it has one, then check and replace fuel pressure regulator. Sounds like no residual pressure on the fuel rail

[SS540i]

S38's have a cam position sensor??? i can't find one on my engine, where is it?

The 3.6L M5's do not have a cam position sensor. Yours is a euro model, but if it is a 1990 then it has the same s38b36 motor as the M5's that came to the U.S

[Amonsta]

I actually just got my maf done at injection labs. Repair was quick. Communication was excellent from Kevin. Unit looked new and the car drives great.

[jint45]

I actually just got my maf done at injection labs. Repair was quick. Communication was excellent from Kevin. Unit looked new and the car drives great.

did your maf actually cause the car to stall?

[Amonsta]

Yes. The car would not stay running at all. Once I installed the rebuilt maf the car stayed at idle. If I recall the repair was around 260. Definitely worth it though. I'd also replace all the Vaccum lines as well.

[SpecRaceM5]

I'm thinking it is a connection issue somewhere. Fuel issues in my experience have usually caused a shuttering prior to stalling. Sounds stupid but did you check and clean the battery ground? Also the alternator ground? Like a few people have said, it is probably something cheap. The price for a cheap fix though is the PITA it is to find the problem. Best of luck to you.

Cheers,

Brian

[ianskinner]

idle control valve clogged up? mine used to stall at lights.

[Benecke]

Hello! I have the same car and I have the same problem! You repaired it?

[kalevera]

Hello! I have the same car and I have the same problem! You repaired it?

It was the DME, IIRC

[Benecke]

Thank you!!
I've already find it)))
http://i83.fastpic.ru/big/2016/0916/9a/2d727c5adb52e049a72b16d8f4e4409a.jpg