A friend of mine gave me a computer chip that is for my car...But when i installed it it would work great if i will doing like 50.....but if i got down into the city they damn thing would just flood out...anyone know why?

 

Who makes the chip? Often times, the aftermarket chips cause more problems than they solve (or promise to solve). Try putting the factory chip back in. If the problem goes away, then the aftermarket chip was improperly coded or damaged.

I had an aftermarket chip in my Camaro; the previous owner put it in. I never got around to replacing it, but I know that it caused idling problems and a severely-rich situation. I finally received my chip burning parts today, and I was able to replace the car's coding with a factory setup. My engine is nowhere near complete (having some valvetrain issues), but the car idled a hundred times better. I didn't have a chance to drive it yet, as a cracked rocker stud ended all of my fun.

Check out the DIY PROM board. If you're into getting the most out of your car, burning your own custom chips is really the only way to go. I still have a lot to learn, but the time spent is well worth it.

 

ya that makes sense, i put the old one back in and it doesnt run rich anymore...there is an idiling problem when i move the car and then just immediatly turn it off...the next time it wont start up and stay running unless i keep my foot on the throttle then after about 10 minutes of driving it kicks out and it will finally idle... you have any idea why it does that? (the happens witht he origional chip)

 

Is your idle air control (IAC) properly adjusted? This controls how much air enters the engine at idle to properly maintain a specified RPM.

Also, ensure that your TPS voltage is set at the factory 0.54. An improper reading can cause problems idling and may affect drivability as a whole.

IAC and TPS adjustment

 

where is the IAC located?

 

The IAC is a cylindrical sensor located directly below the TPS sensor, on the passenger-side of the throttle body. There's a square, four-wire connector going to it. You may have to move a few hoses to see it.

 

ok, so that could effect the way my car idles when it only runs for a short period of time....cause if i actually take it out and even drive it around the block its fine it doesnt have a problem idling...its only when i move the car in the driveway and turn it off that it has the problem.

 

In regard to the location of the IAC and TPS, I'm assuming that your IROC has Tuned Port Injection.

The IAC controls how much air is allowed into the engine at idle. When the IAC valve is closed, the engine is supposed to run around 400-500 RPM; sometimes it won't even run at that low of an idle. The only way that the IAC is fully closed is if it's not working properly, or you're specifically trying to set the idle speed. When you start the engine, the computer opens the IAC valve while monitoring RPM. It's goal is to maintain a specified speed, usually around 650 RPM.

It's possible that the IAC isn't functioning properly, and may not open up completely until the car has reached operating temperature (the same thing as driving it around). Excessive carbon build-up in the sensor is a common problem and sometimes prevents the valve from moving, which doesn't allow enough air (or allows too much air) into the engine at idle.

I'd first try readjusting the IAC, per those instructions I sent. If that doesn't work, I'd pull the sensor and examine it.

 

alright thanks man! I will let you know how it goes