Split second stall then idles again

[Visions]

89 535 automatic,,,, My buddies car is having problems again... the car idles pretty smooth after new Dist and plugs a little while back,,, but now all of a sudden it will stall for a split second and I'll see the check engine light come on and a split second later its idling great again... it does this randomly and doesn't over compensate with a higher idle like others have posted... he says it will stall sometimes when he slows to a stop or is slowing to turn or when backing up... Car does it both cold and warmed up...

Its a little different then other problems I have read about ,,, at least they seam different to me...

This is the closest problem I have found to match his (pulse generator/cylinder ID sensor) what do you think?

http://www.bimmer.info/forum/showthread.php?t=25309&page=2&highlight=engine+stall

Thanks for your help once again

[BillionPa]

when was the last time he replaced the spark plug wires?

[bsell]

89 535 automatic,,,, My buddies car is having problems again... the car idles pretty smooth after new Dist and plugs a little while back,,, but now all of a sudden it will stall for a split second and I'll see the check engine light come on and a split second later its idling great again... it does this randomly and doesn't over compensate with a higher idle like others have posted... he says it will stall sometimes when he slows to a stop or is slowing to turn or when backing up... Car does it both cold and warmed up...

Its a little different then other problems I have read about ,,, at least they seam different to me...

This is the closest problem I have found to match his (pulse generator/cylinder ID sensor) what do you think?

http://www.bimmer.info/forum/showthread.php?t=25309&page=2&highlight=engine+stall

Thanks for your help once again

You say the 'Dist' is new. Do you mean the distributor cap is new or the whole gizmo?

Either way, it sounds like you have an intermittent break in voltage supply to the ignition circuit. Look around at all of the connectors/wires handling the 12v side of the system, especially around the areas you messed with while installing the new parts.

I wonder if his coil is sending warning signs of going south? You would think if the coil was going south, it would be weak causing missfires at high loads...

Brian

[Visions]

Update.... when the temp changed outside and it got warm the problem stopped.... now that it is cold again the problem started back up... could it be the temp sensor and if so where is it located... still may be the spark plug wires but while I was driving it , I only noticed the check engine light flip on and off when I was stopped or taking off...

Today he said his car stalled at a light and it took 1hr to get it going again

[Morgenster]

What about the fuel pump relay? If that goes south it starts to function intermittently. Cheap fix if that's the problem. Of course, in this case it'd also happen while driving and not ust in idle.

[shanek]

How cold is cold? I have similar problems with mine when it hovers around freezing like -5 to + 2 celcius unless I put gas line anti-freeze in. My 325 stalled in traffic once, then wouldn't idle properly,I put some in and it was fine.

[Visions]

Well today it was doing its caughing fit and its warm outside... in the upper 40's....

Fuel pump relay and main relay is brand new


Distributor cap and rotor is new...


I hate to just guess and not be right but I may just put some new wires on it.

[Visions]

Bumping this up... would like to fix this problem before it really gets cold here cause I don't have a a garage

[everlast]

I have the same problem. I was leaning towards cleaning my ICV (525i with a m50). Did you check for vacuum leaks, etc?

[BillionPa]

a loose connection to the icv could cause it, losing its voltage and closing.

[Visions]

Since it wouldn't cost anything I switched out his(535) coil for mine(735i)... with no change, so thats ruled out...

I can see if a spark plug wire is bad there would be a miss fire,,, but the entire car cuts off for a split second and sometimes it stalls because of it... Yet it goes back to smooth idle... I'm certainly not a mechanic... all my knowledge comes from here...

Thanks

[JMI]

Just get the spark-plug wires with the position sensor (http://catalog.drivewire.com/drivewire/baseline/wizard-newest.jsp?partner=drivewire&year=1989&make=BM&model=535-I-002&category=All&part=Ignition+Wire+Set).
They are probably due anyway.

Jim

[everlast]

What does the sensor wire do? Does it replace the lead to a crank position sensor or something, or do our engines have that wire, but the OE sells it separately?

[JMI]

These are 4-stroke engines. The crank position sensor by itself cannot tell if a piston is TDC on it's compression stroke or TDC on the exhaust stroke. The position sensor/pulse generator/cylinder ID sensor, which is on the #6 plug wire, picks up the firing of the plug and then the car's 'brain' knows where in the 4-stroke cycle the engine is.

Jim

[Visions]

Another update,,, the car is now idling rough and stalling more... Called my friend thats a great mechanic and tried to get the car in to him but he's way backed up with work... so I talked to him about it and he said to check the MAF... Not really sure how to check it but I could put mine in his car to see if that works...

While I'm there I can check the ICV

[Dave M]

CHeck the fuel pump connection. Open the cover in the trunk and wiggle the electical connector to see if it will stall or improve idle. I just discovered this issue on my studdering/stalling 525.

Dave M

[Visions]

Another update... Put my MAF from my 735 into his 535 with no change,,, also switched my TPS for his and it seamed to work for a few minutes then went right back to cuttting out again...


After doing that above the next few days got warm and into the 50's and 60 and the car ran fine for 2 days and now it's back to the same condition...



Dave I can check the Fuel pump connection as thats easy...

[Visions]

Could it be a temp sensor making the fuel too rich and stalling it out... strange that if the outside temp gets warm enough for a few days then it runs ok again...

[Morgenster]

An engine cutting out randomly and firing back up makes me think it's entirely electrical. Especially if it's more prone to happen during certain weather conditions. Maybe you shoud check if there's any voltage drops simultaneous to the cutouts. Any connector or sensor that's on the way out gets a little nastier with colder temps in my experience.

[Dave M]

strange that if the outside temp gets warm enough for a few days then it runs ok again...

Exactly what mine would do. Above ~5 deg celcius, ran fine. Below, cut out untill the engine warmed up. Go figure. Check that fuel pump wire. I have photos, but they're at home. The Bentley manual doesn't state which wire is power supply, but I believe its # 5 in the photo they have. Its the top right hand wire in the connector.

I'll post later.

Dave M

[ILoveMPower]

Sounds like you need plug wires or else something fuel pump related. I would check around the fuel pump and make sure all connections are sound.

[bbig119]

I had similar symptoms as you, although ambient temp wasn't an issue. I traced it to the fuel pump, replaced and car is running fine again. After changing fuel filters a month ago it ran fine for a couple weeks and then it started again randomly until I did the pump.

If its the original pump, it might just be a slow death. You should try listening to the fuel pump, and if you can, pressure test it.

[JMI]

It was this thread (http://www.bimmer.info/forum/showthread.php?t=25309&page=2&highlight=engine+stall) that was referred to in original post. It was my experiance with an almost identical issue. Been there, done that...

Just get the spark-plug wires with the position sensor (http://catalog.drivewire.com/drivewire/baseline/wizard-newest.jsp?partner=drivewire&year=1989&make=BM&model=535-I-002&category=All&part=Ignition+Wire+Set).
They are probably due anyway.

Jim

[Visions]

It was this thread (http://www.bimmer.info/forum/showthread.php?t=25309&page=2&highlight=engine+stall) that was referred to in original post. It was my experiance with an almost identical issue. Been there, done that...

Just get the spark-plug wires with the position sensor (http://catalog.drivewire.com/drivewire/baseline/wizard-newest.jsp?partner=drivewire&year=1989&make=BM&model=535-I-002&category=All&part=Ignition+Wire+Set).
They are probably due anyway.

Jim


JMI---Exactly what I thought the problem was when I first posted this problem... I didn't know the spark plug wires and this part were together as a package... now I understand... Damn.... Thanks alot!!!


Thanks to everyone that helped... much appreciated... I will get the spark plugs with the "Pulse Generator" and come back and update this thread...

[Visions]

The Pulse Generator was the problem... got new wires and it runs great again...

My big mistake with purchasing plug wires was I bought them from BavAuto.com and I bought their upgraded wires... The wires sucked.. The part that plugged into the spark plug was so Damn flexible that I had a hell of a time trying to get the damn things on and still I'm not sure if they are on all the way... Why in the hell they would make them like that I have no clue... Trust me I cursed the entire time! The OEM wires socket is hard so you can easily push them on,,, do yourself a favor an never purchase the upgraded wires from BavAuto... I'm going to call them tomorrow and complain big time!

Thanks everyone for your help...

Visions

[JMI]

The Pulse Generator was the problem... got new wires and it runs great again...

My big mistake with purchasing plug wires was I bought them from BavAuto.com
Visions
That is why I included the link (http://catalog.drivewire.com/drivewire/baseline/wizard-newest.jsp?partner=drivewire&year=1989&make=BM&model=535-I-002&category=All&part=Ignition+Wire+Set). Never been impressed with BavAuto's products or prices.

Good luck.

Jim