Hey i've got a quick question i've just got a 1983 trans am and the car idles to high. the car idles at about 1300 rpm all of the time and i was wondering how to adjust it. If anyone could drop me a quick answer it would be most appreciated. the car has the crossfire fuel injection system on it.

 

Is it carb or tbi? Carb you would just adjust you idle screw but for the tbi its the same thing. But it also might not even be that. It could be a mass flow sensor or an oxygen sensor. So you could try that.

 

83,

Your CFI system is in essence two TBI400 throttle bodies mechanically linked. Each of these has an IAC motor, and the IAC is usually the first item to check when idle problems are apparent. Clean the IAC air passages in the throttle bodies. Even if this doesn't slove the idle problems, you will eliminate a potential problem.

Another typical cause of uncontrollably high idle is vacuum leaks. This can be from gaskets, hoses, the power brake booster, EGR system, and the PCV system. Eliminating the brake booster and PCV are easy by simply disconnecting and capping the hoses for testing. The EGR is a little more time-consuming, but not really difficult to diagnose. Hoses are easy to remove and inspect/replace. Gaskets can be the most elusive form of a leak.

On your TBI throttle bodies, there are also throttle stop screws used to set the minimum bypass air position of the throttle plates. Normally, those aren't a problem unless they have been tampered with inadvertently. And there is always the possiubility of a binding cable or linkage, but that is easy to check by determining if there is adequate slack in the linkages when the throttle are closed.

This ought to be fun...

 

hey thanks for the information ill look into it asap.