Engine New AC. Stalling when steering

ggradtech

Active Member
Jun 17, 2016
179
19
28
My 93 has a 351 swap. I had an AC system installed. I have my dual Contour fans run when the engine temp is 180. I also have a relay to run the fans anytime the AC is turned on, so the condenser stays cool when activating the AC. Cars runs great, except when the AC is on and I take slow turns at low speeds. Like in a parking lot. The load of the ps and compressor cause the engine to stall out. Any ideas? Do I need a base idle reset with the AC running?
 
  • Sponsors (?)


You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 250,000 hits, which indicates it does help fix idle problems quickly and inexpensively.
 
The idle is supposed to go up to compensate for the load. If you have a factory computer it should do it automatically. If you a carbureted the way to do it is with a 1990 cadillac deville idle control stepper motor. Wired to a 12v relay it will increase the idle a couple hundred rpms to help with the load from AC and PS at low speeds. It usually only takes about 200 rpm. Stepper motor will not work with efi...the computer will keep trying to compensate around it causing idle issues.