Idle/rpm Surge And Dying

[avar]

New here so I'll start off with Hello. Back to business. I'm not a mechanic obviously since I'm here asking for help on a forum. I don't have money to throw at a mechanic I don't know or trust. I'll start from the beginning. Bought the car back in 2014 and drove it around a bit Its a 1990 LX convertible 5.0. We had overdrive go out so we tossed an extra AoD we had in it. It had sat for awhile and when it was drove is was surging badly Say 3000 RPM to 1000 and so fourth. We parked it again and its been sitting till recently. It also will not idle without some feathering of the throttle left on its own it'll surge from around 1000-500rpm and die. We replaced the IAC and EGR from our other mustang cleaned the PVC valve back in 2014 and didn't fix the problem. I also checked and set the TPS sensor to 0.98. Wondering if anyone has had any issues like this and shine some light on this or give me a check list to go through so I don't replace parts that don't need replacing. Thanks folks

 

[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 200,000 hits, which indicates it does help fix idle problems quickly and inexpensively.