Schipani GT

I have i 93 gt and have been having a problem with it lately that is sumping me. I puta70mm throttle body on it,76mm MAF, fuel pressure reg, 155 fuel pump, smog pump is eliminated, headers and flowmaster ex, and a trickflow track heat intake. The fuel pressure was set at 43 idle and about 50 WOT. The car ran perfect before putting the trickflow intake onit, wich at the same time i took the vaccum line off of the charcol canister, and i plugedthe vaccum linesand alsounpluged the electicalconnector fromit. Ever since i didthat combo itstarts great runs good til it starts getting warm, once it does the throttle starts getting not as responsive. Once warm if i shut it off and start it right back up itwill NOT idle. It surges terrible and shuts off if im not in the gas, but top end wise still runs the same. Sometimes after driving it some it will go away other times it doesnt. I have tried cleaning theIAC and punplugging it and plugging it in and it make no differance.Please let me know of any suggestions.

Thanks, Justin

93must

Try adjusting the TPS? Vacume leaks?

Schipani GT

I set theTPSat 9.8v when i got it and ithought of checking it again i just figured the if it was thatthe problem wouldbe all of the time and not just on warm starts after just running, is that true? And im pritty sure there are no vaccum leaks but if there was, wouldnt it idle rough all the time not just then?

Thanks again, Justin

topless91gt

I had the idle surge too. Ended up being my MAF.
Good luck!

Schipani GT

---I had the idle surge too. Ended up being my MAF.
Good luck---

Was the surg all the time or at times like mine?

kcsoa22

There was also a TSB on intermittent High idle, and it stated to remove the wiring harness extention that bolts to the back of the intake. Remove the extension and reconnect the wire harness. it will be a little bit of a pull, but It will re connect. Solved my problem for almost a year, now it's back again. Maybe not exactly what you have but maybe worth a try?

Chitown racer

First of all why did you set your fuel pressure so high? What other mods are done to the engine, if any? What Brand of MAF sensor are you using? What size injectors are you using? Has the MAF been "calibrated" for the size injectors your using?

topless91gt

It was just every once in a while. Ane just like yours it ran great as long as you were on the gas. When it would surgeI unplugged the MAF and it stopped the surging. I know this is not a good way to check it but it worked in my case.

Schipani GT

It has 19lb injoctors, C&L MAF housing with the changable injoctor test tubes set for 19lb, stock sensor. with the stock fuel reg it was about 41-48 so with all of the extra air now i figured i would add a little morefuel. timing is set at 15is thatthe bestsetting for my set up?

Thanks