EVAP system question

[DeltaSix]

I have been struggling with a wonky idle for about 8 months now. I have replaced the knock, cam, and crank sensors, new ICV, new purge valve. My idle never seems to be quite right. When the car is dead cold it will start and idle around
750. If the engine is restarted before it cools down completely the idle after starting drops to a little under 500, surges a few times then settles around 500 rpm. These hot starts also cause the idle to fluctuate above and below when the clutch is in until the car has been driven for a few minutes. Regardless of what temp the engine is when I start it, after driving the car for a 5 minutes the idle settles around 600 rpm. It also idles quite rich, but this may be due to the Turner chip I have. Anyway, Carsoft threw the code 252 on the DME which is Tank Ventilation System - Suction Fault, Incorrect purge flow. I assume this to mean that one of the lines from the the charcoal canister has a hole in it. The weird thing is that my car is an 02/95 325is and the 252 code is OBDII, which my car is not. Does anyone have some experience with the EVAP system and their possible errors? Am I correct in thinking that a vacuum leak in the EVAP lines could cause a bad idle?

Thanks,
Matthew

[Wayne 962]

Welcome! Those generic code readers are sometimes very misleading because that may be an error message for a different type of car. The best readers are the Peake Research ones made specifically for these BMWs.

You can also use the gas pedal method to get the codes on your car:

http://www.pelicanparts.com/bmw/techarticles/Mult-Code_Reading/Mult-Code_Reading.htm

I would try this, and then report back which codes are being displayed.

-Wayne

[DeltaSix]

Using my peake tool code scanner there are no codes at all. I could never get the gas pedal method to work. This is the wierd thing, the peak shows no errors but carsoft keeps throwing this 252 code. This occurs after clearing the code and rechecking without starting the car. I wonder if it is a bug in the program opposed to an actual fault stored in the DME.

[DrinkCoffee]

I am having this same exact issue.

Also my car idles at 1000rpms (93 325is stock M50)

Does anyone have any further information on this?

[DrinkCoffee]

Bump.

Thinking that this code is wrong or something.

I think my vanos is bad. Car surges to 3,100RPM on cold start, 2-3k on warm start, marbles in can sound coming directly from vanos, idle at 1,000rpm and rarely rough.

Most everything else checked and replaced. NO VACUUM LEAKS (22hg/m vaccuum). New and/or tested sensors.....

[mehamgul101]

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