i have a 94 ls. whn ever you start it the rpms will go to about 3500 the drop down to 1500ish then go back up to 3500. i talked to two mechanics one said it is my tps and one said it might be the idle adjust screw. i bought a new tps but didnt put it on yet and i adjusted the screw and it lowerd the rpms but now it goes from 1000 to 2200 rpms. if anyone has had this problem or please HELP!!!!!!!

 

you might have vacuum leaks..causing your car to surge idle..or air bubbles in your coolant system

 

i took my intake off and put my hand over the throttle body while it was running and it stalled

 

have you calibrated your tps?

 

how do u do that is it in the hanes book i have a new one though

 

put your tps in that should solve your problem..and if not its a vacum hose leak

 

how would you find the vacum hose leak??? I guess what i am trying to ask is what line would/could it be?

Also if its a coolant bubble is it alright to open the rad cap after the car has started to let the bubbles slowly come out???

 

no air = no run

I would start by checking all hoses that go to and from the intake manifold for loose connections or needing replacement

as far as taking the rad cap off once warmed up I would take the cap off while the engine is cold and start the car letting the bubbles escape before there is too much pressure in the system and you get burned

 

im sorry but do you know how long it should take for the boubles to come up

 

yea sorry thats what i meant, just after start up to let the bubbles out......and i will check all hoses from intake to make sure they are nice and tight..

so failing that...what else could be wrong?? my rpms after about 5 min being on will go up to about 2500 and hold for a sec, then drop again to around 1000...

 

i know that no air = no run , now since it stalled that ovously means there are no vacume leaks

 

dont the tps and map have same plug?or i know theres 2 sensors that do(i think)i know obd2 does.i dunno if obd1 is the same..but i know if they are switched it will act goofy like that.
iff not get like a carb cleaner or somthin flamable and spray around tbody gsket,intake manifold gsket area and see if the rpm jumps wen u do.

 

alright i will do that , they do look the same, and i just bought a bottle of carb cleaner today