Cold idle wont come down..
- Thread starter im4darush
- Start date
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I checked the TPS with a volt meter when the car was off with key in the 'on' position. The reading was .60, so I set it to .39-.40. After doing this, I turned the key and the car still went over 2000 and stayed there. Next I went to the IAC. I dont have a scan tool so I turned the screw out until the idle came down to about 1000. Turned the car off and then back on, idle was fine. I know that is not the correct way to set idle, and I may have IAC issues again when the car is cold. I did turn the car off and on a few times and the idle was where it should be. Would the TPS adjustment when the car is off automatically register? Or is a start and restart needed?? That would make sense as it was .60 (way over idle). I guess the only way to really know is to start the car when it is cold and see if it goes back to 2000. Any other advice would be great if you have it.
turbodave231
Moderator
- Joined
- May 24, 2001
- Messages
- 2,287
Sounds like your IAC is not working properly (may be all gummed up) or it may have an electrical problem.
Pull the IAC motor and clean it with carb spray. Clean the throttle blade and inside the throttle body with a toothbrush and carb spray. Set Minimum Air Rate per factory spec then set TPS. The min air rate procedure is listed on GNTTYPE.org:
Service Manual
Procedure
Start car and let it reach operating temperature, turn key to off
1. Ground ALDL diagnostic lead (short the top two rightmost pins in the ALDL connector).
2. Turn on the ignition (but don't start the car).
3. Wait 30 seconds.
4. Leave ignition on and disconnect the IAC connector.
5. Remove the grounding from the ALDL connector.
6. Start the car. The car will probably run rough and may stall. Just restart and try again.
7. Adjust the throttle stop screw to set the idle to 500 RPM +/- 50 RPM with the car in drive.
8. Turn the car off and reconnect the IAC connector.
9. Turn ignition on and adjust TPS to proper settings. (.42-.44 at idle is typical)
10. Repeat procedure until the 500 RPM +/- 50 RPM in step 7 can be maintained while TPS is at proper idle setting.
Pull the IAC motor and clean it with carb spray. Clean the throttle blade and inside the throttle body with a toothbrush and carb spray. Set Minimum Air Rate per factory spec then set TPS. The min air rate procedure is listed on GNTTYPE.org:
Service Manual
Procedure
Start car and let it reach operating temperature, turn key to off
1. Ground ALDL diagnostic lead (short the top two rightmost pins in the ALDL connector).
2. Turn on the ignition (but don't start the car).
3. Wait 30 seconds.
4. Leave ignition on and disconnect the IAC connector.
5. Remove the grounding from the ALDL connector.
6. Start the car. The car will probably run rough and may stall. Just restart and try again.
7. Adjust the throttle stop screw to set the idle to 500 RPM +/- 50 RPM with the car in drive.
8. Turn the car off and reconnect the IAC connector.
9. Turn ignition on and adjust TPS to proper settings. (.42-.44 at idle is typical)
10. Repeat procedure until the 500 RPM +/- 50 RPM in step 7 can be maintained while TPS is at proper idle setting.
