# Formula Firebird idle help **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [July 16, 2008, 6:57pm UTC](https://forums.speedlife.net/t/formula-firebird-idle-help/51619 "2008-07-16T18:57:50Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![HYBOOST](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/hyboost/32/5088_2.png) [@HYBOOST](https://forums.speedlife.net/u/HYBOOST)\ **Post date:** [July 17, 2008, 3:13pm UTC](https://forums.speedlife.net/t/formula-firebird-idle-help/51619/3 "2008-07-17T15:13:27Z")
> [@rubbersiidedown"](#): > > So I just picked up an unfinished project a 1988 Formula and wanted to get some ideas where to start addressing an idle issue . The 305 has been pulled and a 350 is now in its place I believe it to be out of an early 90s truck . All the fuel injection (tpi) has been put back on the 350 , but when started or when coming to a stop it wont keep an idle . It is 5 speed also original to the 305 so I have to keep my foot on the clutch and keep her running . I haven’t dropped the tank but I dont think the fuel system has had any upgrades and doubt there has been any computer tweeking to compensate for the larger motor . Would these be the most likely things to address to fix the issue ? Like I said I have very limited info on the build and I dont think I will be able to get much from the person who did the swap so any suggestions would help . Thanks guys . You have a scanner? You need to watch the _ **T** _hrottle _ **P** _osition _ **S** _ensor, and the **_I_** dle _ **A** _ir _ **C** _ontrol Valve. _ **With the engine off, key on** _ the T.P.S. should read around .3 to .5 @ idle & up to around 4.8 at W.O.T… Numbers should move smoothly from idle to W.O.T. with #'s slowly climbing, not stopping at any one #, than jumping up skipping a bunch of #'s as you slowly push the gas pedal down. The I.A.C. should drop as the engine idle drops. If you blip the throttle (engine running) it should jump up, & as the #'s drop, the idle should follow. If the idle starts dropping too low and you watch the I.A.C. try to raise the idle by raising the numbers, it may be a bad I.A.C… If you don’t have a scanner you can check the T.P.S. with a volt meter. It’s also a good idea to pull the I.A.C. valve and inspect the pintle. Clean it , the housing it sits in and the throttle body itself with air intake cleaner. I don’t think using carb cleaner is recommended. Being very carefull, _lightly_ try to push the pintle in just a small amount. It should move some. Don’t go ruining it by pushing or pulling it in or out more than a few mm’s. If it is frozen in one position, there is a good chance that is the problem. There are a bunch of other things that could cause this but these are a couple quick & common problems. All this assuming the car runs good off idle, no engine miss, noises, etc. Good luck, hope it helps. --- _[View the full topic](https://forums.speedlife.net/t/formula-firebird-idle-help/51619)._