Injection M10B1.8 Stalls when hot, running rich

[webermagic]

Hi this is my first post and I am in need of some M10 expertise. This is the first M10 car I have ever worked on but I am au fait with M30's and BMW of this period.

I have a 1987 fuel injected 1.8 M10 engined car with 96k on the clock that stalls once it gets warm and is then very difficult to start. It has had lots of new parts fitted including. New fuel filter, Dizzy cap, Rotor arm, HT leads, King lead and coil. The air flow meter also looks to have been replaced recently. I have owned the car since November but I have been fettling it and only tried to drive it properly for the first time Yesterday.

I drove the car to its MOT which it passed. I noticed that it had a bit of a flat spot when trying to pull away and when coasting in say 3rd gear, when the accelerator was replied the car would falter as though I was in too higher gear and then it would pick up. Otherwise the car drove fine.

The car was stopped and started several times whilst at the MOT station with no problems. I was then issued my MOT and drove off up the road. I came to some traffic calming, dipped the clutch and it stalled. It started up fine, I drove a little further along the road dipped the clutch and it stalled again and would not restart.
I had fuel and good spark. I did notice the plastic joiner between the body fuel pipes and the engine fuel pipes was wet with fuel and it turned out to be cracked. I replaced it this morning.

Current situation

After replacing the plastic joiner the car started and ran perfectly when cold. I drove it round the block and it performed perfectly. Once it got warm the weird missy thing came back and then after being driven for no less than a mile I had to dip the clutch and it stalled.

The pattern seems to be that when its cold/cooled down it will start and run perfectly. How ever as soon as it's warmed up any manipulation of the throttle will cause it to stall. I removed the plugs and found each one was black! I have fitted new Bosch Super fours and the symptoms have persisted.

I tried running the car with the Air slider valve unplugged and it made no difference, the car ran perfectly until I touched the throttle. Unplugging the thermo time switch which also made no difference and I got the same story when I unplugged the cold start injector. When its hot, as soon as you touch the throttle it dies. I also tried forcing the throttle open with the throttle stop and it still stalled.

TPS is clicking but looks oily.

Any ideas on what could be causing this would be gratefully received.

Many thanks

[aimlessrock]

have the injectors been overhauled lately ?

[webermagic]

have the injectors been overhauled lately ?

Not that I am aware of, are the injectors on M10 cars prone to failure?

[webermagic]

And the answer is!!!

Air flow meter.

Dispite having a "new" AFM it is actually a reconditioned one and the reconditioning must have been done by Stevie Wonder! The flap has clearly been sticking as there are marks where it has been jamming. A very clever friend of mine came and looked at it today and managed to dress the offending part of the flap inside the air flow meter which was catching and hey presto it works lovely. Car starts and drives wounderfuly now.

Thanks for viewing.