Idle quality not worth a damn after heads/intake/cam

thesource · Feb 16, 2006

I recently installed another engine in my wifes 94 Gt . Its a 90 model stock short block with an E cam , 1.72's , 93 cobra intake and ported E7 heads . I am using the 93 style EGR on it as well . The car runs fine while driving except for an over heating issue but at idle it sometimes just starts rolling up and down real bad and will usually just die after about 3-5 seconds . I have messed with the MAF and its clocking , I have adjusted the idle , the tps is right and it doesn't have any vac leaks . Any ideas ? I have heard the 94-95 computers do not like cams . Any truth in that ? I have thought about drilling a small hole in the throttle blade because I know alot of the LS1 guys do that to get them to idle decent after a cam swap .

Matt94GT · Feb 16, 2006

Yes cams and 94/95s dont go well. Do a little test for me, unplug the IAC harness and start it up, does it seem to idle better and not fluctuate as much? If so you can make a IAC plate that will help that problem. Did you clean your IAC? Clean your MAF?

Personally I find I just gotta keep my foot on the throttle to about 1,500rpm for like 15 seconds then its good to go.

QIKGTS · Feb 16, 2006

That cam should idle fine even with the crap stock calibration. It sounds like an IAC issue to me. Drilling a hole isn't a bad idea to help get some more air past the throttle blade, as Ford even sold a kit for this exact purpose. IIRC, you would drill a hole in the throttle blade, off the car of course, and then you could install your choice of a couple different sized orifices to help trim the air flow. Ford also sold that plate deal with the air bleeds on it that installed under the IAC.

Are you using a Fox throttle body too? If so make sure all the egr lines are hooked up right and leak free, especially at the nipple on the throttle body. Often those nipples come loose or crack right at the base. You could chase that forever until it (the nipple) finally falls off in your hands...

wiplash · Feb 16, 2006

Is it auto or 5 speed?

thesource · Feb 16, 2006

The car is a 5 speed , I do have a 70mm PP throttle body on it , I am using a fox style IAC but used the SN style first (no difference except the SN one howled like a dog through the filter) and the EGR set up should be fine .

badass98svt · Feb 16, 2006

sounds to me like you may have a leak after installing the cobra intake.
a bad intake gasket will cause an irratic/searching idle

NITROUSINJECTED · Feb 17, 2006

badass98svt said:
sounds to me like you may have a leak after installing the cobra intake.
a bad intake gasket will cause an irratic/searching idle

werd man just intalled a motor in my 90 hatch and it did the same thing b/c of an leak in the intake and a vacum leak

QIKGTS · Feb 17, 2006

I just reread my post and realized I meant the "pcv" fitting on the throttle body, not the egr. That's the one that often breaks off the fox tb....

OMG, erroneous info on the internet, there's a suprise....

wiplash · Feb 17, 2006

:gtfo:

thesource · Feb 17, 2006

I doubt its the intake but I will double check it . I have a 1/2 spacer between it with brand new gaskets .

NITROUSINJECTED · Feb 17, 2006

HAVE YOU CHECKED ALL YOUR VACUM LINES MIGHT BE A LEAK THERE

Matt94GT · Feb 17, 2006

he said he did, next time ur snooping around unplug your IAC harness and see how it runs.

bcknblack · Feb 17, 2006

justa little info i wanted to install the e cam into my 94 and was told that the 94-95 computer will not accept the cam change i was told to run a 93 or earlier eec computer in my car seemed like a lota trouble so i stuck to the good ol trusty stock cam

olice:

Matt94GT · Feb 17, 2006

you could get a tuner like a Tweecer or PMS to solve the problem.

Lightning Struck · Feb 17, 2006

Hmmm, sounds like it needs tuneing

Monsterbishi · Feb 18, 2006

Personally I'd be looking into the overheating issue first, if there are pockets of air running past the coolant temp sensors it could be causing the ecu to drop into coldstart mode.

Does the idle sound like it builds up in a curve, and then drops down sharply?

thesource · Feb 19, 2006

I figured I'd have problems with the 94-95 computer and this cam . I just wanted the wifes car to have a little rumble to it and it does when it idles correctly . I doubt it has anything to do with the over heating issue . I think thats the POS radiator in it . I am going to swap the radiator out with a larger aluminum version and while I am there I'll pull the intake and check the gaskets and vacuum lines at the same time . More than likely its going to needa tune which sucks ......... hate to spend the money on such a little combo and a daily driver .

Lightning Struck · Feb 19, 2006

thesource said:
I figured I'd have problems with the 94-95 computer and this cam . I just wanted the wifes car to have a little rumble to it and it does when it idles correctly . I doubt it has anything to do with the over heating issue . I think thats the POS radiator in it . I am going to swap the radiator out with a larger aluminum version and while I am there I'll pull the intake and check the gaskets and vacuum lines at the same time . More than likely its going to needa tune which sucks ......... hate to spend the money on such a little combo and a daily driver .

I had a x cam in my 95GT and it went crazy, never could get the computer to deal with the cam swap and had to end up putting the stocker back in it, everything was fine from then on. This was in 95 or early 96, since then parts have become available to deal with the pussy-fied computers in the 94 to 95GT's.

95CALI-5.0 · Mar 16, 2006

Yeah, I agree. A tune should solve your problems

Z28 This · Mar 20, 2006

how hard and what exactly what i have to get to change my 95 computer and harness to a 93 computer and harness...i was at the strip and some guys at a swamp meet were tellin me different things so i dont know...im going engine work and 94-95 computer are a bitch to tune..