1989 Fox, 5.0 High Warm Idle

[hamirick]

Hey Guys,

Hoping for some guidance here. You guys have been a huge help so far, so thank you!!!

Alright, so, I'm new to actually adjusting an engine. I've swapped parts, and done chassis/suspension/body for year, but actually "tuning & adjusting", etc, I'm new to.

Right now, my cold start idle is about 500 - 700rpms, feels perfect for me. But when the car warms up to 190 - 200 degrees, the idle jumps to 1500 - 2000, which is way too high. Is ther an adjustment for the warm idle that I've overlooked? I used the adjustment bolt on the throttle body to set the idle, am I missing another adjustment screw/bolt or is this an electrical problem, etc?

Please let me know!

Thanks!

 

[Mustang5L5]

Perform "idle reset procedure" and then drive around a bit and run the engine codes

 

[jrichker]

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.

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.

 

[Real time recon]

Seems to me 500 to700 cold start RPMs is a little low.