Scrooge

I have been dealing with recurring idle problems for some time with my C-4. I have already replaced the DME relay, but the problems remain. The first start this morning left me with a very rough idle that jumped all the way to 1100 rpms and held before finally coming down after several throttle blips. The car ran pretty poorly for about five minutes. Additionally, when I do a quick, light stab on the throttle, I am usually greeted with an engine speed that slightly falls and then stutters before returning to normal idle speed. This problem does not occur all the time, but often enough to make it frustrating. Could the above symptoms be caused by an oil overfill condition? If so, what is the proper course to remedy the problem? Any thoughts on this issue would be greatly appreciated . . . thanks!

Jeff Curtis

If you have in fact over filled the oil, then there will be some in your intake/airbox. I'm not sure if this is causing your issues but you can try cleaning out your intake.

The simple way to do this is remove the airbox cover and air filter, then remove the rear half of the air box from your "barn door" unit...this allows easy removal of the "barn door" sensor and then you can reach down in the intake/throttle body with rags and wipe the oil out.

Your situation sounds like it might be more than an oil overfill, but then with cyber-diagnostics we can only speculate.

Ade - C4 91

Hi Scrooge

This is a problem my C4 has been suffering for a long time without a real solution found by any of the service agents i've been to. Its great for the first 500 miles after service then it becommes iratic and unfriendly. DME reset does not seem to fix it.

Now after replacing just about everything (each having an increased level of success), I've come to the conclusion it's a faulty airflow meter. this is the next and hopefully the last part to be replaced.

You could try to clean the little coil potentiometer in the airflow meter and see if that helps. Also make sure that the connectors' cables at the rear of the meter are not too close to the oil pipes. There is a service report on this.

Good luck.

Ade
91 C4

Adrian

Guys,
If you read the thread restarted by Slant911 you will see the repair to the connector at the airflow sensor I posted. I recommend you try this first before paying for rather expensive airflow sensor assemblies. For the record, any comtamination of the airflow sensor by vented excess oil will cause these problems. The clean up must be complete. This involves removing the entire airbox assy and cleaning out the entire airflow sensor assembly. Just cleaning out the airbox is not good enough.
Ciao,
Adrian
911C4

Ade - C4 91

Hi Adrian,

So you're saying is that if the Airflow sensor has been contaminated once, then it wont clean itself and the problem will (not surprisingly) continue.

What do you suggest for cleaning - will Carb cleaner be ok. Can the sensor be dammaged easily?

Ade.