Help!!!

I need help.
88 sefi and computer off an 88 tbird.
I have replaced the Map sensor , EGR valave , EGR sensor , TPS sensor , PVC valve , ICS , and the TAB.
The car idles fine when cold but as soon as it warms up it starts to surge from 950-1200 . If I bring the rpms up to about 1500 it smooths out fine.
What could possible be the problem?
I am at my wits end. I am really considering just driving it off a cliff .
Someone please please help!
Email me or instant message me (preferably cause we can discuss it in real time)
[email protected]
MSN - whattfisuphotmail.com
AOL - Deadguy249th
Yahoo - deadguy249th
HELP!!

I would help, but I don't know much about it. Sorry, and hope you find someone to help you.

Ahhh yes the Infamous idle surge! I think everyone fights this at one point or another.

Is the motor modified at all? Is the computer throwing any codes? When you replaced your TPS did you set it's voltage properly? Have you replaced or cleaned the IAC, located on the side of the throttle body? I fought a warm idle surge for ages. I finally bought an Idle air control plate that mounts between the TB and the IAC valve. It seemed to work pretty well.

How do I set the tps voltage? I thought they were not adjustable.

Have you checked to see if the car has a vacuum leak yet?

You want the TPS voltage to be set under 1 volt. Setting it to .93 to .98 is good range and should be fine. The risk of a surging idle increases quickly the closer you get to 1 Volt.

Loosening the two bolts on top of the TPS, will enable you to turn the sensor slightly left to right. This is how you adjust it. Now you will have to back probe the black wire (negative) and the green wire (positive) of the sensor with a multi-meter. In some cases the bolt holes of the TPS might need to be elongated to achieve the proper voltage reading.

With that out of the way try this.
Set your timing to where you want it, 10* is stock, advancing a little to 12*-14* might be good.
Now reset the cars computer.
Do this by disconnection the battery for 20 minutes. Reconnect battery, unplug IAC motor, and start the car. The motor may have a hard time starting and you may need to give it a little gas to stabilize the idle. Once the idle settles, adjust the idle stop screw to about 700 rpms. Adjust TPS voltage to .93v-.98v.
Shut car off. Plug IAC motor back in and start the car.
Let it idle for 2 minutes with all electrical accessories running.
Shut engine off for 2 minutes.
Let it idle again for 2 minutes with no accessories running.

What you are trying to do is get the computer to learn these new settings. By disconnecting the battery you erase previous settings, in preparation for the new setting you just made. Try this and let me know the results.

-Craig

Sidenote:
Closer you can get to 1volt without being at 1 volt the better pedal response.

Originally posted by GTStang
Sidenote:
Closer you can get to 1volt without being at 1 volt the better pedal response.

The TPS should never be set above .95-.98 volts at idle. Doing so brings it dangerously close to the 1 volt point at which the ECM determines you are driving rather than idling, and a rough, hunting idle often results. Besides, there isn't a human alive with reflexes quick enough to tell the difference between .95 and .98 volts, so don't buy into the hot rod hype of adjusting it too high (anything above .98 volts is too high).

Ahhh yes the Infamous idle surge! I think everyone fights this at one point or another.

Is the motor modified at all? Is the computer throwing any codes? When you replaced your TPS did you set it's voltage properly? Have you replaced or cleaned the IAC, located on the side of the throttle body? I fought a warm idle surge for ages. I finally bought an Idle air control plate that mounts between the TB and the IAC valve. It seemed to work pretty well.


Hi;

I wrote a message to you, Hiflow5 0 about the IAC Plate, where can I purchase one, or what are its specifications and maybe I can make one?

Thanks,

Gil_McC
[email protected]

Hi;

I wrote a message to you, Hiflow5 0 about the IAC Plate, where can I purchase one, or what are its specifications and maybe I can make one?

Thanks,

Gil_McC
[email protected]

A few companies make them they are all the same. I just found this one real quick through an internet search. There is a good picture showing where it goes. I've had good luck with using them especially with a cam swap. Also a good way to cheat and not change ya torque convertor for certain cams.


http://www.windsor-fox.com/spacer_plate.htm