e30m3 Fuel Delivery Problem

Need_To · 10-21-2009, 05:09 PM

I can't keep her running? Sometimes I can get a cold start but rough idle at about 2k rev's. I belive she is flooding. smell gas will not restart etc. Is there a cold start injector that could be stuck on? There is a Bosch instrument part of the air intake manifold what is this? I have checked the air flow meter, temperature switch, pressure switch etc. any thoughts would be much appreciated.

Ceeker · 10-21-2009, 05:27 PM

I don't believe there is a cold start injector independent of the injection system. the older M20's had them and they upgraded as well past the 87 year. check o2 sensor.
too much fuel tells me MAF meter isn't regulating the mixture. Cold start injector always come on in this weather. I don't think the car would do this at fresh start up. it would only do it when the car is warm.

A faulty O2 sensor would make the car run crappy. Disconnect it while the car is running and see if it changes anything. If the problem goes away while disconnected then it is your 02 sensor. You might see a increase in the idle or stabilization of the motor running. if nothing changes then we know it's not that and something else.

hope this helps.

Need_To · 10-21-2009, 06:17 PM

The part I was refering to is the throttle position switch? I disconnected and checked the air flow meter resistance values over it's range of travel ... what values should I get? If I can get it started it will not accept any throttle at all the mixture seems way off. Normal idle should be less than 1k rev's.

Aveman · 10-22-2009, 01:06 PM

You could have this

http://www.s14.net/forums/showthread.php?t=6426

If that's the case your idle control motor is gone and you need to get new transistors soldered onto your ECU.

Test your idle control motor and go from there.

Need_To · 11-08-2009, 01:35 PM

Well my new ICV finally arrived and I installed it yesterday ... but now no spark ...nothing I checked the DME for burn't transisters but nothing obvious ... there is a 3rd switching transistor on the DME ... could this be the one for firing? ... looking from the coil end it looks like they ground the coil to generate a spark pulse .... cause I have 12vdc on both terminals .. the resistance values seem ok .6 ohms and 5600ohm's, I may change all 3 transistors on spec and try to find a good scope?