driving everywhere without any probs and then I come to a stop light, the tack starts going up and down same with the engine idle speed, almost to a pint of stalling.... so I pull over and pop the hood to see whats going on... hmm cant figure it out... although when I give it some gas and hold it at say 2000 rpms it does run good without it going up and down like I said before....

it has a 302 and its a 5 speed 2 barrel manual chock carb

all new wires are on it

any ideas?

 

Does it accelerate of does it just go lower than idle speed?

 

I only noticed the idle speed going up to 1500 rpms and then sinking down to about 200 rpms almost to a stalling point, this is just at a stop... so what I have done is hold the gas pedal down to about 2000 Rpm's so it doesnt stall....

now this ideal speed goes up and down and dose not stop doing it... its like its doing it at an even pace... up to 1500 rpms down to 200 rpms back up to 1500 rpms down to 200 rpms and so on..

 

Sounds like a vacuum leak. Check all your vacuum hoses for cracks.

 

ya I was thinking the same... went over them and they seem ok shurgs

 

do you have a power brake booster? does it only do it with the brake pedal pushed down? its definitely sounds vaccum related

 

yes I do have power bracks... the funny thing is when I take off the vaccum hose to the brake hub thing the idel speed goes up alot but it it stays up without going back down .... it dose the same thing if I take off the other hose going to the valve cover ideals faster but the take stays up without goina back down,,, when I put the vacume house back on it starts over again going up and down.

 

just so you know I have replaced the lil ball thing that the vacuum hose goes to on the valve cover I was thinking it was the prob but its still doing it.

 

Vacuum hoses are about 63cents a foot. Buy about 6 feet and replace all of them. Vacuum hose leaks are hard to find, so with replacing them all you will have eliminated that possible source of your problem.

 

could the cap & rotor make this prob also? I have never changed that part yet and it looks a lil old...