willeyboy

I recently purchased a 98 gt with a 4.6 car runs solid plenty of power has a cam, cold air intake bbk long tube headers im havin trouble with it idling it seems to be worse when at operating temperature but it comes and goes sometimes i stop at a redlight and it idles fine at about 650 to 700 rpm other times it starts out fine then jumps to about 1000 rpm back to 650 rpm then shuts right off. i replaced the IAC valve and that did not fix it i checked the fuel pressure at the rail it was runnin about 34psi but did not lose pressure when the engine shut off so im not sure what the problem might be like i said its only during idle and it comes and goes and seems to be worse when at operating temp...any suggestions?????

JCON

clean the throttlebody. a dirty/sticky plate can cause this issue. Cheap to clean.

willeyboy

i will try that 2maro...will let u know the result thanks

TRUEBLUE3934

Mine exhibits the same general behavior ever since I installed my cams. I have never been able to correct this condition.
It seems to be more likely to happen if I have the wheels turned (loading the power steering) or if I still have the brakes applied.

Keep us posted on your analysis!!!

willeyboy

Finally got around to cleaning the throttle body it def was in need of that unfortunately it did solve my idling troubles so im still open to sugestions and appreciate all help

TRUEBLUE3934

Too bad that didn't help you!

I did clean my TB butterflies this weekend, AND I cleaned my IAC while I was at it. So far, the idle seems to be controlled better and I have not had it choke off on me since. However, I haven't driven it much since so it is too soon to say that it fixed my troubles. I'll post up in another week or so and follow up on how mine is doing.

I had NEVER cleaned my TB until now (78,000 miles). I did replace my IAC with a new FORD Part right after my cams were installed (2.5 years ago).

TRUEBLUE3934

I drove my car quite a bit today under the conditions in which it typically had trouble maintaining the idle. I will absolutely say that cleaning my TB and the IAC have corrected my choking off issue

I don't know why I didn't try cleaning the TB before, but I think that was probably what was causing my troubles. Oddly, it didn't appear to be very dirty, but a fair amount of dark fluid ran out when I sprayed it down real well with carb/choke cleaner(and scrubbed it with a toothbrush). Obviously, it was dirtier than I thought.