Can American Muscle Help???
I have a 94 Mustang GT, that isnt exactly stock. I have: Cam, cold air intake, Pro-M MAF sensor, 70mm throttle body, 24 lbs injectors, Dyna Mod tfi module, Performance Distributors distributor, stock heads and intake manifold, and custom exhaust work with an off road xpipe and full 2 1/2 inch exhaust.
After driving the vehicle for about 5 minutes, the engine wants to idle at 2000 rpm. I unplugged the IAC motor, and did not change a thing. I eliminated the EGR valve and the EVAP purge valve to eliminate those as possibilities. Throttle body, MAF sensor, and Cold Air Intake have been changed with no difference in symptoms. I have a wide band air/fuel ratio gauge, and my readings are perfect, suddenly it leans out for a few seconds, then the idle acts up, but the air/fuel ratio goes back to normal. I connected my SNAPON scan tool, I have no codes, and verified correct tps reading at closed throttle (0.97v). My MAF sensor reads normal voltage at idle and when snaping the throttle open. Now, keep in mind, this is also before the problem occurs. I cant get the scanner hooked up when the problem occurs, because I dont want my car just sitting at 2000 rpms while setting my scan tool up. I smoke tested the intake and verified NO vacuum leaks. I have an SCT 4 Bank Eliminator Chip tuned by Bama Performance thanks to American Muscle, but I removed the chip to eliminate that as a possibility, and problem is still there.
I recently had this problem arise when I hooked my vehicle speed sensor up to the car, where I did't have it attached before because the speedo was way off due to me recently installing a different rear gear ratio.
I'm pulling my hair out, running out of ideas of what could be causing this... Other thoughts of mine are the Constant Control Relay Module due to it supplying the main power to the PCM, Injectors, Evap Purge Valve, EGR, and MAF sensor, or the TFI module and/or Distributor as a possibility of timing concern...
Sent from my VK810 4G using Mustang Evolution mobile app