idle problems help

notch351

Member
Jul 30, 2010
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I bought a 94 5.0 and the previous owner installed afox throttle body swap to car. othe than that is just has your basic exhust edlebrock intake and other simple mods. the car surges at idle when you first start it for a min. then once driven for amin seems fine. I know these 94-95 stangs are tricky have checked for the norm stuff vaccum leaks exc. note the car also has one of those adjustable iac plates on it. any help would very much like to fix issue. the car has no chip or anything tune wise.
 
Try this link... its worked on mine. Id recommend all the steps if you never set the idle or TPS voltage. My Fox swap has been problem free on the idle and such and your mods shouldn't be doing jack to hurt it or throw things off.

The Corral
 
I did do the tps when i first bought the car, but I guess it is probably off now from me trying to mess with that stupid adjustable iac. I did also try to remove that and once i removed that peice the car wouldn't hold an idle at all every time i would put in the clutch and come to a stop the car would die so i put the adjustable plate back on and been trying to deal with it ever since. the car also has the egr removed but i did by that little plug in sensor that sends the single to the computer the the egr is operating normal. so I guess i will try to check the tps again to see where its at. thanks
 
Been there had that...clutch in, it dies. Check the voltage then do the other steps...odds are the TPS is fine..I find they very rarely move once set.

Clutch in and it stall is more in the later portion of the reset...it needs to learn to idle with a load on it. Do you have a stock IAC to throw on in place of the adj one???
 
yeah the stock one is still on the car the adj plate goes in between the throttle body and the iac. it has 2 set screws you use to adjust the air through the iac. was gonna double check the tps and take off the adjustable plate for iac and try to reset idle.
 
so i removed that iac plate went through the steps - the tps adj and it seems to be doing better. idle a little high but i am sure the tps needs a little adj because i had it loos to set it and my buddy didn't bring over his multi meter so i did process with out. let you know how it is once i reset the tps
 
well after trying to reset the idle i am concerned my problem has something to do with the egr being deleted and the trouble code not being cleared and bypassed with a delete selinoid to trick the computer
 
Mines gone as well along with the smog tubes to the back of the heads...everything....As I mentioned....you set the EGR plunger 1/2 way & secure...puter see's all is fine...never had a CEL.
You have a sensor that plugs into the factory EGR plug that does the same I guess??
 
i seem to remember that usually indicates a rich condition. the computer usually tries to make is richer for a little while after starting.

does it do that both when cold and hot?

did you clean the mass air meter sensor?

is the timing set at 10*?

perhaps the coolant temp sensor has gone bad?
 
it only does it on cold start up. have cleaned maf and also put new one on just to ck. timing is set at 14 degrees. haven't check the temp sensor. guess i could reference ohms and ck it. and i do beleive the computer is making the car run rich for that brief time