won't stay running when i first start it up

[sodaking663rd]

i only drive my '93 gt every other week or so. i have quite a few mods to the car and it drives pretty well after it's been driven for a few blocks. i have an e303 cam, trick flow heads, billet mass air meter, gt40 intake, 65mm throttle body...can't think of any other mods that may affect this rough starting problem.
i have to continually rev the car or it will stall right when i start it up. also when i'm driving it the idle at first seems to stay around a steady 1700-1900 rpms...it will drop within 30 seconds or so to about 900-1000.
i had the mods done on the car years ago done by a pretty good mechanic.

do any of you know anything i can do to fix my stalling out problem or high idle after driving a bit? perhaps i shouldn't expect the car to drive like a stock mustang with the amount of mods i have done to it?

thanks as always for any input.

 

[willys1]

1900 is way to high.Mine does that but only for a second then it comes down.I just had the same problem with it stalling.I think it was the temp. change.I had the Fuel pressue real low for the track(it ran faster that way).But all the sudden it kept stalling when Id start it up in the morning.I increased the pressure and the problem was solved.What does yours Idle at when its warm?

 

[Legendary]

I have a friend that just got his car put together with the same heads and the f303 cam and had the same problem. We adjusted his tps to .99, checked his timing and played with the idle screw on the throttle body. It starts up fine now and idles at 900 rpms. He hasn't driven it 5 miles so the computer will have to adjust to the new mods also. But it stays idle after tickering with it.

 

[sodaking663rd]

i'll have to take a look at the fuel pressure at idle...i have a mechanical gauge on the hood.

the throttle position sensor...where and how do i adjust it? what degree of timing should i set it to? i understand the timing varies but i'd like to have some idea. Thanks both for your help!

 

[Legendary]

14* seem to work for him. The tps is on top of the throttle body (I'm sure you know that since you knew what tps meant). You'll need a volt meter. The positive side of the volt meter goes on the green wire and the neg side on the black wire. You take a screw driver and slightly loosen the two screws so you can sort of nudge the tps. You'll have to go clockwise or counter depending on where it's set to now. once it's set you need to tighten it back down. You will need somebody to tighten it as you hold the voltmeter to the wires because it doesn't take much to knock it off track again. Hope this makes sense.