95' 740i: Check engine light often goes on and stays on; car stalls freq. at lights

[kentscrivener]

I'd really appreciate it if someone could give me a little help here. My check engine light comes on frequently. It stays on for for a while and then goes off. Often times when I'm at a stoplight the car will stall out. The car is easy enough to restart, but I'd really like to get this problem taken care of.

My mechanic has run the OBD, but nothing shows up. He has not yet been able to diagnose the problem. He thinks it might be a vacuum issue.

Can anyone shed some light on this so that I can relay this info to my mechanic?

Thanks.

[IcemanBHE]

Well..since your car isnt ODB, I wonder what codes your mechanic is going to find? Hope he isnt charging you.

You need a diagnostic laptop with a REAL ADS interface to check for codes on a 95.

Or look in the DIY forum above for info on a stomp test...

But my guess is a bad MAF or going out crank sensor...

[WarMachine7]

Well..since your car isnt ODB, I wonder what codes your mechanic is going to find? Hope he isnt charging you.

You need a diagnostic laptop with a REAL ADS interface to check for codes on a 95.

Or look in the DIY forum above for info on a stomp test...

But my guess is a bad MAF or going out crank sensor...

This, listen to this man.

"There can never be peace without war"

[Sobek]

But my guess is a bad MAF or going out crank sensor...

You mean camshaft sensor right? Or can a failing crankshaft sensor still affect a car while actively running? The stalling when coming to a stop sounds like a classic camshaft sensor issue to me.

[WarMachine7]

You mean camshaft sensor right? Or can a failing crankshaft sensor still affect a car while actively running? The stalling when coming to a stop sounds like a classic camshaft sensor issue to me.

Yea but the crank sensor constantly measures the rotation of the crankwheel dont it? Well luck thing is all three can get checked but we are just swinging in the dark till the op does the stomp test, op if you are a visual learner like me go to youtube, they have the stomp test procedure in there, search for "e38 stomp test"

"There can never be peace without war"

[IcemanBHE]

Pretty sure I meant Crank Sensor.:crazya

[Jamos]

If you disconnect the iac this would happen. Make sure it's clean and properly connected.

[miguel760ti]

Cool thing about 95s is that you don't necessarily need a code reader for codes

http://forums.bimmerforums.com/forum/showthread.php?1433734-HowTo-gt-OBDI-Stomp-Test-video-(M60-only)