1994 Mustang GT Idle Problems

mustangguyjs · 04-07-2008

I have a 94 GT that seems to miss under a light load. The car is mainly stock but the gears, cai, pulleys,and exhaust. I pulled the plug on the iac and the car shut off. Is it supposed to or is this a problem. I replaced the vac hoses,intake gaskets,tps,iac,adjusted the timing,and a new computer. Also put new plugs,wires,cap and rotor, and a new msd blaster coil. Any help would be appreciated.

stretch101b · 04-07-2008

sometimes it does that when u put a cai on and check ur o2 sensors

**EagleAutosports** · 04-07-2008

If it cut off when you disconnected the IAC, that means it's good.
That sounds like either a vacuum leak or a timing problem.

mustangguyjs · 04-09-2008

Thanks for the advise, if you have anymore suggestions please tell me

cindys_sn95 · 04-09-2008

CLEAN YOUR MAF IT WILL RUN LIKE NEW!

mustangguyjs · 04-09-2008

I forgot to mention that I have a performance chip (don't know if these go bad or not, haven't heard of any going bad) and I also installed a new maf, so no need to clean it yet but thanks for the advice.

mustangguyjs · 04-12-2008

I installed a fuel pressure guage today and I might have found the problem. I was only getting a little over 25psi and its supposed to be between 30-45. I ordered a adj fuel pressure regulator. I'll let you guys and gals know if that fixes the problem.

greenlantern · 04-13-2008

Just for the record the car shouldn't shut off because you pulled the IAC. I mean if it did that means the IAC is working but thats not a good thing. The IAC is there to compensate and add extra air when the computer tells it too as needed. You need to disconnect the Iac and make your adjustments so that the car will run without it. Then plug the IAC back in.
And plug in off the shelf chips usually don't go bad but I don't recommend them either. If your adjusting the fuel and timming why do you need the chip? All it is gonna do is advance the timing and maybe increase the A/F curve. Here you are making adjustments to fuel and timing yourself and the chip is doing it too. May be to much for the stock computer to handle. Ditch the chip and make your own adjustments. The only good chip is a custom tuned one.

mustangguyjs · 04-13-2008

I'll check on the IAC adj. The chip I have is a custom tune from a local dyno shop, not a cheapy chip from a parts store. Thanks for the suggestions. Keep them comin.