318is Rough Idle - Engine Code 1215

[bebes2k]

I have a 91 318is with 291,000 kms. I just recently bought it with a rough idle and hesitation under load.

I've checked the engine fault codes to determine where the problem may be and I got code 1215 which is a mass air flow sensor fault.

Could this be caused by a bad air flow meter itself? Or vaccuum lines that connect in to the intake boot? The intake boot itself?

Have you heard of 318is' having faulty air flow meters?

I appreciate all the help!!

[bahnfire]

yes i have

[mgold]

I had a rought idle that was traced to a vacuum leak. Turns out it was a hole in my intake manifold gasket.

[e9nine]

vacuum leaks are the easiest to diagnose. I am almost done replacing my hoses...the car sometimes idles a lil rough on start up...I'll eventually get to replacing them all :roll:

[bebes2k]

I've done a bit of diagnostic testwork to determine if my MAF is not working properly and needs to be replaced.

I've determined that the ECU is not sending a proper signal of 5 Volts to the MAF and is instead only sending 0.5 Volts to the MAF via the air inlet temperature sensor from the ECU.

From here, I guess I have to look at a schematic to find out where the temperature sensor is and maybe replace that, if not, it seems that I may need a new ECU.

Can you think of anything else?

[Jordan]

Since when do e30's have MAF's?

[bebes2k]

Do you prefer AFM?

It's a case of same shit different pile.

[demlotcrew]

bill how are you getting the fault codes?

[bebes2k]

The standard key in the "ON" position and depressing the gas pedal 5 times in 5 seconds.

[demlotcrew]

and what does that do? is there something on the dash?

[bebes2k]

The problem has been solved!

It took replacing all the vacuum hoses in the engine bay, the intake boot and the upper intake manifold gasket.

It now runs and idles like it should!

I will post a few links on how to check faults using the gas pedal a little later on...you could also search this site, that's what I did!

[e30Matt]

and what does that do? is there something on the dash?

The check engine light flashes a sequence of flashes which, when you count them, come out to a four digit numeric code.

[demlotcrew]

thanks mate, but do all the IS have this? i know the M20's do.

[e30Matt]

Yes.