For people with rough idle problems

[SDatl404]

I have an automatic 1994 firebird. I was having a problems with a rough idle. My car would idle around 800 in park and about 600 in drive. I replaced plugs, wires, 02 sensors, gaskets and nothing fixed it. Anyhow to the point...

I decided to try new TPS and IAC. Installed the IAC and there was no change at all. BOO. So I didn't have much hope in the tps, but when I installed the TPS and started the car. WOW it idles at about 1200 in park and right at 900-1000 in drive and idles smooth again!!! I am going to drive this around and test it, but I am pretty certian I fixed it!

[turbohead2332]

Re: For people with rough idle problems

My ECU was throwing a low voltage code for the TPS. :P My car was doing almost the same thing.

[nascar24jd]

Re: For people with rough idle problems

When I bought my 93 Firebird it had the same problem. I replaced the IAC and TPS and it has been perfect ever since, about a year and a half now.

[94kah-mer-oh]

Re: For people with rough idle problems

my carzs got the same problem but i have no idea what the IAC or TPS is can anyone tell what they are

[turbohead2332]

Re: For people with rough idle problems

my carzs got the same problem but i have no idea what the IAC or TPS is can anyone tell what they are

IAC = Idle Air Control. I'm not sure but I think it's near the intake/throttle body. I know the IAT is Idle Air Temp, but I don't know if it's the same thing. If it is, it's on the bend in the intake elbow. If your piston rings are fried, you'll find oil in the intake elbow coming in through the PCV valve. Sometimes they get coated in oil from said PCV valve and they malfunction. Just clean it off with a sensor safe cleaner. (That is IF the IAC is the same as the IAT. :P) The TPS is the Throttle Positioning sensor. It's on the passenger side of the throttle body. There are 2 star screws holding it in. It's like a $25 part from AutoZone if I remember right.

[ViperRider]

Re: For people with rough idle problems

Whats the normal RPM our cars should be in during park and idle?

[cam98aro]

Re: For people with rough idle problems

Whats the normal RPM our cars should be in during park and idle?

mine idles around 1000 rpm

[landj]

Re: For people with rough idle problems

Good info! Problem --> attempted fixes --> solution. Excellent!

[Firebirdkid96]

Re: For people with rough idle problems

[QUOTE=turbohead2332;814545]I know the IAT is Idle Air Temp, but I don't know if it's the same thing.[QUOTE]

I always thought that IAT was Intake Air Temp. wouldn't it make more sense for the car to be monitoring the temperature of the air going into the engine rather than the temp of the ambient air at idle?

[HeadyFirebird'00]

Re: For people with rough idle problems

intake air temp = IAT

[FirebirdGT]

Re: For people with rough idle problems

IAC = Idle Air Control. I'm not sure but I think it's near the intake/throttle body. I know the IAT is Idle Air Temp, but I don't know if it's the same thing.

NO, they are NOT the same thing. The IAT is in the air ducting BEFORE the TB, the IAC is in the intake manifold AFTER the TB.

[IwannaCamarosoBad]

Re: For people with rough idle problems

Well my car idles at 1000 but every once in a while it'll start to idle like it has a cam in it. Friend says vaccume leak .... idk?

[Firebirdkid96]

Re: For people with rough idle problems

Yeah thats a vacuum leak.

[HaroZC]

Re: For people with rough idle problems

Well my car idles at 1000 but every once in a while it'll start to idle like it has a cam in it. Friend says vaccume leak .... idk?

check O2 sesnsors too, mine used to idle like it has a cam, but, when i changed O2 sensors the problem was corrected, mine is a '94 3.4 and O2 sensors for 3.4s are very cheap.