i put my 70mm tb on the other day and the car idled fine and the next day i went to start it and my idle stays at 200 rpms. i checked and its not stuck open. when i got the tb it hade no gasket so i made one from that cut out gasket kit. And i cleaned the iac and installed a new t.p.s any idias./
idle probs with 70mm
- Thread starter stangman1
- Start date
Adjust the idle set screw? Or maybe reset the computer (make sure you idle it for 2 minutes with no accessories, then for another 2 minutes will all accessories).
Here's a more technical step-by-step procedure: Click here.
Here's a more technical step-by-step procedure: Click here.
R.J.
Member
Try adjusting it like this, the adjustment is not all electrical so the computer is forced to readjust. After a TFS H/C/I/T-body on my buddies 94, we tried everything to get it to idle and not stall, this was the only thing that worked!
MECHANICAL IDLE SETTING
'94-'95
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.
MECHANICAL IDLE SETTING
'94-'95
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.
R.J.
Member
R.J.
Member
Zero Signal
Active Member
Might be an issue with the ISC neutral idle air flow in the eec. That's all I could think of. A 70mm tb will throw that off. But then again if other people do it, I don't know why it wouldn't work for you.
R.J.
Member
94TURBO5 O
New Member
bimmertech said:
Depending on your skills, how well did you make that gasket?
157 MAF below minimum voltage
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Methodical
15 Year Member
stangman1 said:
I had the same problem and the IAC was bad. The idle was high. I disconnected the IAC plug and the idle didn't change. I replaced it and ok. As one previous post said it may be a vacuum leak. Good luck. Peace
