I've posted this problem before but never quite gotten a real response...I'm driving an 88 Iroc -z 350 tpi automatic with the minor problem of stalling.

Normally I would just get in my car and go but a few months ago (a week or so after I bought it) the car would stall if I threw it in reverse, stall if I through it in drive and stall if I eased on the gas (I always had to jam the gas to make it go). However, if I start the car up and let it warm up for a bit then throw it in reverse and ease out (any gas while in reverse kills it) of whatever parking space the car is in I'm usually alright.I've solved a dozen problems and still I'm left speechless...the car now won't stall but tries to at any time I ease on the gas (which makes turning corners rediculous).

I've fixed a major vacuum leak at the plenum, replaced injectors, fuel filter, spark plugs (platnum 2), wires, cap and rotor (all msd), timing chain (a feat if you ask me), checked fuel pressure (came out fine), checked vacuum (came out fine), checked compression (came out surprizingly fine), I've replaced sensors including the MAF (though this wasn't the problem I took the part back and kept the old one).

Now for the fun bit...I'm throwing a code as you might imagine but I can't read it...I've connected professional diagnostic equipment to this thing and nothing...I've paperclipped it like crazy and nothing (I worry that there might be a short from the aldl to the ecm)...we've gone so far as to replace the ecm only to find nothing wrong with it. One of the many things that makes me believe it might be a wiring issue is that the iac isn't getting power to it at any time...its basically fully extended at all times...

I've put so much work into restoring this car both mechanically and cosmetically (I've replaced the entire interior, fixed dents and fixed the gauges as they weren't working when I got them) that I can't stand to be beaten this badly (I've tried selling it and the best offer I've gotten has been less than a grand).I'm ready to rip the dash out and check every single wire and even then I don't know what I'm doing (I'm electronically impaired).

Anyone who has any idea of things I can do...please let me know. Is it possible that its just a short or a faulty relay that might cause the ecm to not receive or give out the right information from/to the sensors? If so where would I begin?

Thanks.

 

when you check it for codes... it gives nothing but 12, or nothing at all?

You know this for a fact? What did you do to find this out? I think this is a pretty good giveaway to the problem. Perhaps chase the wiring from the IAC, and see where it goes, if anything is "amiss". I don't know how the IAC works, but does anyone know if you can "hotwire" it, to test it out?

I'm no computer expert here, but I saw your thread wasn't getting any replies, and you were considering selling

 

Regarding the IAC:

Pull out the IAC valve. Measure the distance between the tip of the pintle and the mounting surface on the housing. If this dimension is greater than 1-1/8", you need to reduce it, or it'll damage the valve, which it may have already done.

There are two types of IAC valves. Type 1 has a colloar at the end where the elecrical connector is, and Type 2 does not. To adjust Type 1, apply pressure to the pintle with gentle side to side movement. To adjust Type 2, push on the pintle and turn it clockwise until it is set.

If you do decide to replace it, be careful, because there are two different size pintles. One is 10 mm and one is 12 mm in diameter. Make sure you get the right one or it won't seat right.

 

whats your idle set at?

 

Regarding the Iac...I'm pretty sure its not getting power as its supposed to get power when the car cranks at least and it got nothing (used a test light). I'll have to check the pintle thing though...

As for the idle its set at factory specs (for the adjuster screw) and we set timing at the factory spec which dropped the rpms down to around 500-600...as it sits now its probably more like 1000 (we adjusted up timing to compensate).

I've been thinking about chasing the wires...ya never know..thanks for the response guys. Any other ideas?

 

so where is the timing set?

 

I've got the timing set at 15 degrees when it should be 6 degrees