car stalls out when first started

[CRXsk8er]

i got a 89 gt and when i start the engine up for the first time of the day or when its ben sitting for a while the rpms will drop and it will stall out if i dont feather the gas. and it will come real close to stalling and ill give it gas and it will like pop from under the hood like a back fire in the intake maifold. and help would be helpful

[HiFlow5 0]

It could be a couple diffferent things. TPS, timing, dirty IAC. First remove the IAC that is attached on the side of the throttle body and clean the inside of it out with carb cleaner. This will remove built up carbon and allow the Idle to me more controllable. Reinstall the IAC and then follow these steps.

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