Ok, I replaced my IAC and TPS (its a 3.1 V6 91 camaro, I try on the v6 boards but get no love). I put it in diagnostic and kept the key on "on" for 30 seconds and unplugged the IAC. I adjusted the idle and without the IAC plugged in it idles at about 550, which is what I want, with the IAC it stays at 1500 =(. I don't understand why after I do this and plug my IAC in it stays at 1500, even after I let the IAC relearn itself. I don't think you can adjust the TPS on these cars and I can't fix my timing until I fix this idle. Im desperate here, been having this problem for 4 weeks now. Can anyone offer some ideas?

 

I also need to mention that I had it checked for vacuum leaks and it has none. This problem is baffling me. I bought it used and the original owner was stumped on this problem as well. Is it possible the ECM is bad? Anyway to reset it? Im just out of ideas here. Please help.

 

bump

 

Help =/.

 

Is your coolant temperature sensor active and reading correctly?

 

Yes, it works fine, the electric cooling fan kicks in on time as well.

 

If you have access to some data logging equipment, it would be good to look at target idle RPM and the distributor pulses (reported RPM). You've got an odd one there.

 

Damn..my car does that. Right after I bought it, it was having problems like, sometimes when I let it idle it would die..=\ I put in a new IAC and cleaned the little place where it goes and it only helped a little.. Then I removed the throttle body and gave it a thorough cleaning and for some reason it worked after that..
It still does that though..but idles high and eventually settles low. Guess that's more normal though.

 

Well, I was thinking it could be the throttle body, but man I have no idea where to start after replacing the IAC and TPS.

 

Ok, just bought a new throttle body and that seemed to help a bit, my idle doesn't bounce as much as it did, now Im idling at 2500, I have a feeling its my TPS. Anyway to adjust the 3.1 V6 TPS? I know thier auto adjusting but is there a workaround to say just twist and lower it so I could at least test it?

 

when you were adjusting the minimum air rate to 550rpm how
much did you have move the adjusting screw?
while its running 2500rpm, do you hear a loud sucking sound from
the throttle body area?
compare the IAC pintle diameter vs the new one. if you had to "close"
the blade your IAC isnt properly seating.
your going to need a scanner to communicate with the computer
to find out the information:
IAC postition & counts
TPS voltage
O2 voltage
CTS temp on start up
airdeano

 

when you were adjusting the minimum air rate to 550rpm how
much did you have move the adjusting screw?

Not much, i'd say about 3 full turns or so.

while its running 2500rpm, do you hear a loud sucking sound from
the throttle body area?

Nope, never.


compare the IAC pintle diameter vs the new one. if you had to "close"
the blade your IAC isnt properly seating.

Thats not the problem, it fit right in.

I wish I did have a scanner to check all this =/. Unfortunatley I can't afford one right now nor know someoen with one =/.

 

There is a procedure for "teaching" the IAC position to the ECM on the V-6s. You don't often get lucky enough to just slap one in there and have it right. Search the archives, and you might find it. .

 

I was having problem just like this. When I would start my car up it would start up at 2 grand and then slowly go down as it warmed up, while in gear at idle it would be at a grand.

Honestly I have no clue how I fixed it. I disconnected the positive battery cable for a day or 2 to do some work on the car, and not it starts up perfectly. Idles at about 600 RPMS while in gear.

Sean

 

Vader, could you please tell some search words please? Not sure what to look for, thanks.