My car won't hold an idle lately , it just stalls at every stop. I added a ground and replaced a stripped battery cable and the car held an idle after I kept on the gas for a while. I jumped the ALDL connector and the light was flashing quickly after idling for a a few minutes. Then after around 10 minutes it abruptly stalled and I heard a clicky buzzing coming from the IAC. I unplugged the IAC and the noise went away. I started the car without the IAC plugged in and the car wouldn't hold an idle still but the hesitation and backfire popping went right away.
I had this problem or a similar problem before and it got better with a new O2 sensor last month. During the troubleshooting for that I swapped IAC's with two I have laying around. I have no idea if they are good or not, but it didn't change the idle condition at all..
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01:56 PM
PFF
System Bot
avengador1 Member
Posts: 35467 From: Orlando, Florida Registered: Oct 2001
Im sure you know this, but the IAC adjusts the air into the plenum at idle. It sounds like yours is shot. It shouldn't be buzzing, it might click as it adjusts itself, but I would think that buzzing is bad. That sounds like it is stuck. Try one of the other ones you have laying around and see if they do the same thing.
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02:42 PM
alienfiero Member
Posts: 638 From: auburn, wa., usa Registered: Aug 2004
The IAC was one of the only things I didn't buy new so I went ahead and bought a new one and installed it. No change. I have a code 44 now. Lean Exhaust. I drove around up to 40 mph, but the idle still won't hold.
Make sure that the IAC is adjusted correctly. You need to have the pintle fully retracted to make the adjustment. jumper the a & b terminals of the ALDL connector, the, with the IAC out of the TB, turn the key into the on position. This will probably take a couple of tries, but unhook the IAC connector when the pintle fully retracts.
I don't know if you have a 4cyl, or a 6, so I can't be sure of the measurements, but mine was a maximum of 1 1/8" from the shoulder (with the gasket off) to the tip of the pintle.
Make sure that the IAC is adjusted correctly. You need to have the pintle fully retracted to make the adjustment. jumper the a & b terminals of the ALDL connector, the, with the IAC out of the TB, turn the key into the on position. This will probably take a couple of tries, but unhook the IAC connector when the pintle fully retracts.
I don't know if you have a 4cyl, or a 6, so I can't be sure of the measurements, but mine was a maximum of 1 1/8" from the shoulder (with the gasket off) to the tip of the pintle.
HTH,
Dave
Thanks I'll try this out tomorrow. I just made sure that it wasn't sticking out all the way and then I screwed it in.
[This message has been edited by connecticutFIERO (edited 10-11-2004).]
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08:14 PM
Oct 12th, 2004
alienfiero Member
Posts: 638 From: auburn, wa., usa Registered: Aug 2004
I was wondering, if when I get my pressure reading and if it is low which could be the cause of my car not holding an idle, lean exhaust, and stumbling on acceleration what parts might be to blame other than the Fuel pump or the FPR? I saw a fuel sending unit on the F store web site. I also saw a Fuel pump relay. I imagine the relay either works or it doesn't. So that leaves either the pump or the FPR right? The Filter is new but the pump and FPR are old. The sending unit is probably just for the fuel gauge right?
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01:16 PM
Fie Ro Member
Posts: 3735 From: Soest, The Netherlands Registered: Sep 2001
In diagnostic mode the IAC makes quite some noise (calibrating). I really suspected it but after hooking up a fuelpressure gauge it appeared the new fuelpump that was sent to me was the wrong one. It put out 8psi (nice for a carburator) and the new replacement acdelco ep240 puts out around 38psi on the fuelrail and the engine runs great now.
In diagnostic mode the IAC makes quite some noise (calibrating). I really suspected it but after hooking up a fuelpressure gauge it appeared the new fuelpump that was sent to me was the wrong one. It put out 8psi (nice for a carburator) and the new replacement acdelco ep240 puts out around 38psi on the fuelrail and the engine runs great now.
How much was that pump by the way? I notice the Fiero Store has 2 types. An electric for $80 (stock I think), and a high pressure pump for like $150 or something.
