so i have a 305tpi in my camaro the previous owner had done some changes to it like a hoter cam but the original computer is stil in. now the car runns fine wile crusing at 1900rpm and reves fine but when stationary its like it doesent find a stable idling speed it stays at 750 but then goes up to 1100 and stays there for 1 or 2 seconds and then goes back down to 750, stays there for 1or 2 seconds and then goes back up to 1100 and just repeats that again and again but after a couple of times it goes to 500 instead of 750 and eventualy it dies. however if i slightly touche the gas before it dies it somtimes goes back to 750 and holds there for some time but eventualy it will start going up and down again. also if i brake to stop at a stop light it dies if i dont put it into neutral and give it gas. and the last problem: if i put it into drive and stand on the brake it dies as soon as the transmission kicks unles i give it gas at the same time. Now i am wondering could this be becouse the cam is to big for the original computer? if that was the case wouldn't there be some problems at higher rpm's as well?

I hope someone can help me with this, i really want to get this car going for the summer.

Sorry for my bad english im from iceland.

 

The computer has the most trouble dealing with idle, when the engine internal parts are changed. High RPMs are much easier for it.

This cam here is known to work well in an unmodified 305 TPI car. http://www.summitracing.com/parts/CCA-08-501-8/ It still might require some tuning, but should behave almost like stock.

If your car is a MAF one (85-89 or whatever year it was), check the plumbing of your PCV system carefully. There should be 2 hoses from the throttle body, one to each valve cover; the one to the left VC should have the PCV valve in it, and the one to the right VC is the "make-up" air, to replace what the engine draws out of the crankcase via the PCV. This last line is behind the MAF, such that the "make-up" air is metered by the MAF on its way to the PCV valve. A common mistake people make is to put a "breather" in place of the one on the right, which allows unmetered air into the system, which totally confuses the computer at idle and makes it impossible for it to inject the right amount of fuel because there's air coming into the engine that it's not aware of.

 

should the hoses be sort of loose in the valve covers or should they need to be pulled out with some force?, also could this be becouse of a failing idle air controle valve?