My 94 Gt Has Major Idle Issues. When You First Start The Car It Seems To Do Ok ( Cams Nice) If It Would Only Stay That Way. When It Warms Up Idle Surge Takes Over So Badly The Car Shuts Off After About 2 Or 3 Surges. Mods Include B Cam, 1.7 Crane Rollers, Stock Heads Ported And Polished, 1/2 Intake Spacer, 65mm Ford Racing Throttle Body, Shorty Headers, No Cats Or Smog, Msd Cap And Coil. I Have Not Changed The Mass Air Or Fuel Injectors. How Ever I Just Went Through All Seals And Have Replaced Sencors On Throttle Body Along With Constant Control Module ( Thing Near Rad.) Help Please !!!!!!!!!!!!!! Tre.
Idle Freakout
- Thread starter SINGLETON
- Start date
DarkProphet
Founding Member
Davin
Founding Member
have you scanned for codes? Are you sure you plugged your O2 sensors back in? Did you do all that stuff you listed since the last time it ran okay?
I have noticed the cold weather bring's on the surging...All year long mines fine...When the cold stuff hits the idle goes nuts...Try holding the idle high for at least a minute first thing in the morning...Gives it time to catch up...then let off it and see if it'll settle, if it wants to surge again, give it another minute of high idle...Works for me anyway...
a50sn95
Founding Member
You have enough mods to cause idle issues. Some on here will say it can be adjusted out, but I say you'll need a tune....
Basically, you are flowing a lot more air at idle than the computer is programmed for, so it's trying to make your car idle at it's "programmed" airflow numbers.
Here's another recent thread along the same lines:
Here
And the numbers I used:
Here
Basically, you are flowing a lot more air at idle than the computer is programmed for, so it's trying to make your car idle at it's "programmed" airflow numbers.
Here's another recent thread along the same lines:
Here
And the numbers I used:
Here
DarkProphet
Founding Member
You wont have to do that. As long as you get a nice chip burned, or tweece it. It will be fine. I dont know of a single person on here who has had their car professionaly tuned, and not had their problems go away.
AT LEAST I HAVE A ATTACK PLAN:SNSign:
Davin
Founding Member
Not to go against the guys suggesting the tune, but I'm not totally convinced that's what you need and you never want to tune around a problem.
Can we start over for a sec..#1 question: What has changed since the last time your car was running well?
Can we start over for a sec..#1 question: What has changed since the last time your car was running well?
xkuntrycowboyx
Member
check ur vaccuum lines
also ur IACT sensor, right after the maf, make sure you plugged it back in, that will do that... or if it's bad.
i forgot this once..haha just a dumb error, but WOULD NOT IDLE!
also ur IACT sensor, right after the maf, make sure you plugged it back in, that will do that... or if it's bad.
i forgot this once..haha just a dumb error, but WOULD NOT IDLE!
I second all of this. Ford motors are really sensitive to vacuum leaks. My 'stang wouldn't idle at all when cold (it would die in 15 seconds), and had a horrible idle when warm. Replaced one cracked vacuum hose, and the 'stang purrs like a kitten.xkuntrycowboyx said:
The MAF can also mess up your idle if it's dirty or bad. Unplug the MAF sensor wire, and start the car. If the idle doesn't change, your MAF is bad. The IAT sensor, the sensor in the rubber intake hose, can also be bad. Do the same thing; unplug it, then start the car.
a50sn95
Founding Member
mo_dingo
20+ Year Stangneter 
Once the engine warms up it runs rough? Or after 2-3 minutes of driving? That will tell a lot.
scott
scott
R.J.
Member
Have you tried mechanically reseting your idle? Give this a try:
Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.
The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.
Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.
Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.
Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.
If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC. You are done.
Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.
The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.
Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.
Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.
Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.
If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC. You are done.
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