drhoward

Hey I just swaped in a new intake manifold and tb onto my mustang, and after start up the rpm's are jumping up and down to 2500 rpms back down to 1600. I am pretty sure that there aren't any leaks (I had my mechanic look it over, I was getting some gears installed anyways), has any body else had this problem before? I though maybe it was the throttle position sensor but my mechanic thinks it is fine. Does anyone have any suggestions

Cheers
Kev

ZachW04Stang

Have you hooked a vacuum guage up to a vacuum port? Thats the easiest way to tell if there is a vacuum leak.

viking396

Check out the TPS sensor, a mechanic "thinking" it's fine is not the same as proving it's fine since throttle surge is usually caused by an out of adjustment TPS....

drhoward

Thats what I was thinking, I was just wondering if there is anything else that could cause this, how do you adjust the tps if it is out anyways ( I have never done it before)

Thanks
Kev

viking396

The previous poster made a good point, make sure you have no vacuum leaks as well. Check out this thread for TPS help Forum Link

drhoward

thanks alot for all your help

kev

viking396

No prob, good luck!

drhoward

Well I found out what was wrong with it, I went to pick it up from the shop and it was idiloing at around 800 rpms and stalling, the mechanic said it was surging up and down.... so I asked him if he had set the idol on it, which he hadn't.... at least they are cheap there 300.00 cdn to install gears and part of my intake ( I had a bad fuel leak at first)

thanks again
Kev