High idle

[MaxwellSpy]

Hi all
  Been a while since I've been on here. Making some headway on the car. Brakes have been completely rebuilt and are functioning as they're supposed to. Got most electrical gremlins sorted no longer killing batteries. Have replaced all temp sensors but still have no temp reading on the dash. Fixed the fan switch so the fan doesnt run constantly. Replaced the oil pressure sender but still no reading on the dash. Have gotten the engine firing first time, every time. Found a massive vac leak coming from the egr, replaced the gaskets, held my tongue just right, started the engine aaand the extreme high idle is now a sort of high idle with seeking rpms. Going to replace the   iac valve and tps, see if that fixes the problem. Want to make it out to one of the meetings in the car as soon as its road worthy. Hope everybody is having as much fun as I am

[f85gtron]

"Missed it! By ttttthat much!"  Sorry, couldn't resist

[f85gtron]

It's common to get 3or more temp sensors in a row (even from Napa) that are bad. Two things to check:
1) make sure you've got a functioning thermostat installed correctly. If any coolant gets by, it won't get warm enough (usually) to move the needle.
2) to test circuit, insert paperclip into one of the two leads in the guage sensor (located at the end of the head, if v6, then close to ignition coil) .  Ground the paperclip to the block. One lead, when grounded, will peg the guage, the other will turn on the coolant idiot light. That will prove the circuit either good or not.
Hope this helps.
Ron

[MaxwellSpy]

Ron,
   I appreciate the help! Ill give that a go tomorrow!

[Fierofool]

The temp gauge, when the car is cold and hasn't been started, should move to the 100 mark with ignition turned on without starting. 

Ron knows how to reset the IAC without taking it out.  If he can explain that to you, it might save some work and money if it works.  Also, if the battery has been disconnected, the car won't run or idle correctly until it's been brought up to operating temperature and driven at road speeds for about 15-20 minutes. 

I recently tested a number of EGR solenoids prior to putting them out for sale.  They all set a code 32.  I had to disconnect the power to the ECM to clear the code, and when I next started the car, it wouldn't stay running, wouldn't keep an idle and ran like Raydar's favorite word.  KWAP!  After driving it about 50 miles, everything was back to normal. 

You don't need to drive a Fiero to the meeting to attend.  Earlier this summer, we had a meeting and no one drive their Fiero. 

[MaxwellSpy]

Would the iac cause the engine to seek? I prob need to drive it and let the ecm reset

[Fierofool]

Yes.  But there's some debate as to whether it is the cause or the result of the IAC being adjusted to correct other issues.

The EGR valve or tube or one of the vacuum lines poorly connected or cracked can be the actual cause.  I'd try driving the car first and see if it settles down, then delve into other areas. 

[MaxwellSpy]

Temp gauge all the way left and pointed at the roof of the car with the key on, engine off. I ran Ron's test and got no joy from the light or gauge

[Fierofool]

I went back to see if I could identify what car you had and I could only find this thread.  No information.

If you have a V6 car with the 85 mph speedometer, I believe I have a good complete gauge clusters.  It 's from an 85GT with 104,000 miles.  All you would need do is slip the odometer out of yours and into this one (very easy to do) and you'd have the correct mileage for your car. 

[f85gtron]

Iac reset procedure:
1) Jump aldl a-b,
2) Switch ign "on", but no start, (ses light should be blinking codes)
3) unplug iac after 30 seconds (it should be making noises before unplugging. Its being commanded to seat/extend fully)
4) shut everything down, remove aldl jumper, disconnect battery, eat dinner.
5) after 30 minutes, plug iac back in, reconnect battery.
6) start car (It may not idle good)
7) once warmed up, drive somewhere that will allow you to drive for at least a couple minutes over 35mph. During that time, there iac will be commanded to fully extend again and the ecm will learn it's range. The car won't idle correctly until this procedure is complete.
Ron