PTskater944

Well a few weeks ago i was having trouble with the car idling low and not starting up when warm. We adjusted the idle and made it higher, also that apparently took care of the warm startup problem. I still want to replace the DME relay just in case though. Things got worse yesterday morning though. The passenger door wont open from the outside or inside, the driver door is hard to open from outside but will open from inside. I also went out into my garage yesterday morning to drive to school and my driver side mirror had somehow fallen out and was shattered on the floor. I started it up, and at least it idled right. For a while. Through my neighborhood the engine sputtered and hesitated when i got on the gas, also backfiring a little bit every once in a while. The sputtering and poor throttle response got progressively worse as I drove it. I was giving my friend a ride to school, his house is halfway between mine and the so I wanted to at least get it to his house. It barely got there, it started idling lower than ever before (like 200-400) RPMs, and eventually it started just dying every time I left off the gas. Luckily it started back up every time, but i had to hammer the gas as soon as it started to keep it from dying (throttle response was really bad, the engine was sputtering all the time and giving it half throttle only revved it up to 1500 RPMs or so for a while. I got it to my friends house, my friends dad took us to school, and while i was at school my dad and Ben from imagineauto came and drove it to imagineauto. I dont know how he got it there, maybe it ran better when it had cooled down or something. Anyways heres the basic summary of whats going on with my car

Sputtering when accelerating and backfiring (i'm pretty sure this is a vaccuum leak after reading clarks-garage)
Really bad Idle. Could it be caused by the vaccuum leak?
Car is running extremely rich- this could be a part of the bad idle I think, but not all of the problem.

With my logic, I think there is either something wrong with the DME, or various sensors are giving the DME bad information, or both. I don't think theyve started checking it out at Imagineauto yet, but what are some things they should look for?

-Bad DME, or bad solder joints
-Bad DME relay
-Vaccuum leaks
-O2 sensor
-Throttle position sensor
-Air Flow Meter

Anything else i'm forgetting?

Then once all that stuff checks out, see if the idle can be adjusted. After that its going to another shop for a couple minor leaks and an oil pan leak and then some bodywork (hopefully get the doors fixed too) and then repainting. I'll be glad when all this is over. Thanks for any advice or help you can give me.

jerome951

Vacuum leaks should make it run lean, not rich.

From what you describe, disconnect the connector at the AFM and clean the contacts. I had the same problem before and this solved it.

Likely not an O2 sensor; that only causes a wandering idle, but doesn't cause the car to die.

As a test for the TPS, unplug it and see if the idle gets any better.
A bad DME relay usually causes the engine not to fire at all, so I think that is OK.

dime1622

i still say DME relay. when mine went, it had cut the motor off a few times previously. then one day, it cuts the motor off, and wouldnt start back up. let it sit a little bit, and it would start up, but the idle would be fine for about 2 mins, then the idle would start slowing down, and after a couple more minutes it would just be so slow it would die. never rule out a bad DME relay. make sure to buy 2. always good to have a spare.

PTskater944

OK update:

They re-soldered the contacts on the DME and replaced a temperature sensor, and throttle position switch which helped out a lot. Its still running rich but it doesnt sputter, backfire, and die anymore. We think its the oxygen sensor making the car run rich. Also the compression is low. It goes 140 (about normal), 90, 115, 120. What could be causing that? The head was completely rebuilt a few months ago, if that would have anything else to do with it.

fast951

Do a leakdown test, the compression numbers don't look good. If the car was running overly rich for an extended period of time, it's a good idea to set the correct AFR and drive the car a bit before doing the leakdown..