so ive done just about everything i know to my car but im still having issues with the idle. its a 350 tpi and ive replaced the vacuum lines and cleaned out the throttle body and replaced my idle air control valve with seemed to fix it for a while but now the problem is starting again. the problem is that when it is cold it will idle fine but as soon as the car warms up the idle will start getting lower until the computer makes it rev up more. so it will go back up and down for as long as you let it then as soon as you go to take off it will die and when you go to crank it back up the moter will turn over as if it cranks but it wont idle until the car is cold again.... what could this be?

 

Does it throw any codes? If so I would look at those first. Check the easy stuff first, fuel pressure, timing, etc. But from what you described it sounds like its probably fuel related meaning fuel pump or injectors. I've seen bad injectors do exacty what you are describing.

 

the coils on the stock injectors are prone to failure especially when they are warm/hot. When they made these injectors, the internal coil is exposed so as fuel runs through them over time they fail. A quick way to check them ohm them out when they are cold and hot. Anything below 12 ohm needs to be replaced.

 

I had that problem a few years back and it was a pain, mine was a small vacuum leak at the back of intake gasket

 

well theres no codes on it at all the service engine light isnt even on. i also checked my fuel pump. (its works and is fine) and ive replaced my fuel filter and im still having the same problem. checked the iac again and still trying to hunt down a vacuum leak (wheres some pics of all the vacuum lines? just so i know im looking for) but im still having the problem. it idles fine until it warms up then the idle dies a little untill the computer raises the idle so it just lopes back and forth all the time.... ive checked the trusty haynes manual and it says check for vacuum leaks and the fuel system... theres no tags on the car so i cant drive it and test it but if it wont idle right it wont drive right? lol

so do you guys really think its the injectors or what? ive put some injector cleaner in it but i cant drive it so that wont do me any good....

 

so i guess my quistion is how do you hunt down vacuum leaks?! i do hear a hissing and idk where it comes from and whenever it starts to die down it gets louder... im thinking thats my best bet right now.