My e34 runs fine then dies out

[Coldaccord]

My e34 runs fine for a couple minutes, then starts running like **** and won't move. Thought it may be a clogged cat so I pulled the exhaust off, it's running open header right now. Put a scanner on it; no problems, even though once it starts running like **** it throws a cel. It said it's getting 1.12v at the o2 sensor, but the o2 sensor isn't on there.

I just dont understand because it runs perfect for the first few minutes. good steady idle, etc. I don't understand what it could be? As soon as it starts warming up it dies out. When I put the scanner on it when it started running like **** after I started it and ran it for a couple minutes it was at 54 degrees celsius (~129F)

any ideas? coolant temp sensor? sending unit?

[bmwrp8]

check the temp.sensor, and might help you better if we know what kind of e34 that you drive

[Coldaccord]

92 525i m50

[Coldaccord]

anyone?

[DaveCN]

Andre,

Have you tried swapping out the coolant temp sensor yet?

That would be one guess.

[ahlem]

What happens if you run it with the gas cap loose? In the driveway, not on the street. I'm wondering about a fuel pressure issue or a clogged fuel filter.

[Dave M]

I'm assuming it does the same thing with the exhaust removed.
As BMWrp8 said, check the temp sensor. Actually, check both the engine temp sens and the coolant temp sens. The two are located below the intake man. and can be seen in the left of the photo below cylinders 1 and 2.



Bentley has the testing procedures. However, if I recall, the coolant temp sens involves boiling water etc., so isn't super friendly to diagnose. You may want to try removing the harness for each one while the engine warms to see if one is suspect. The DME will allow the engine to operate with either of the sensors disconnected.

Otherwise, a cat code could be one of many things, including throttle position sens, ICV, CPS........... Let us know what you find.

Dave M

[Coldaccord]

it was a bad dme