rockinh

I have a 95 gt that started out while driving at highway speeds and come to a stop it would sometimes stay at 2000 rpm. If i turned the car off and back on it would idle normal again and everything was fine. I was told by a friend that it was either the IAC or the TPS so i changed both of them and now the was will not idle below 1300 rpm at all and when you drive it and go to shift gears as you push the clutch in it will idle up to almost 4000 rpm. If you are sitting and car idling at 1300 and rev the engine it is very very slow to come back to the high idle of 1300. When I changed the IAC and TPS I disconnected the battery for a while and for some stupid reason didn't check my codes before because the guy that told me what the issue was is usually pretty knowledgable with these cars but no such luck this time.

Since i change the IAC and TPS and the car when from just a periodic high idle that could be fixed with a restart of the car to a constant high idle even when idling i put the old IAC and TPS back on and still have the same high idle issue.

Please any help would be great I need to get this car back on the road.

rockinh

Also something else to take in account. If i remove the air intake off the throttle body still with all sensors hooked up it will idle down to around1000 but not all the way to the normal 750-800 range. Then i hook the intake back to the throttle body and it idles right back up to 1300. It is still slow to idle back down if revved up with air intake hose off though.

dawson1112

Did you make sure the tps is set properly after your replaced it?
They need to be set so at idle the voltage is around .98v After you get the tps set then you can do a base idle reset.

There are numerous topics on line about both of these if you look it up.

rockinh

I did not and i have not a clues how to do that.

HACKGT350

where did you get the iac from? i have had a lot of problems changing ford iac's with aftermarket ones make by companies like standard.

rockinh

It is aftermarket, kinda on a budget since I'm having drive 125 miles round trip to work in a diesel that gets 10 mpg since my car is down.

HACKGT350

do yourself a favor and get a motorcraft one. every ford that comes into my shop that needs an iac gets one from the dealer. any aftermarket one we get does exactly what yours is doing.

rockinh

what are the chances that is the issue because i can't afford to buy $150 dollar part from ford i can't return and that not be the issue.

dawson1112

Adjust the TPS and do a base idle reset.

TPS adjustment

Base Idle reset.
http://fordmustangcar.com/repair-and...-set-base-idle

Project 5.GO!

I'd have to say you should go right to the TPS and base idle reset with this one. If that's not it, go to a junkyard for an OEM IAC to rule it out as the source. Look for one that looks decent, inside an out, to minimize the chance that you end up with a bad one. Clean it out with some carb cleaner and Q tips before you install it.