1994 Mustang GT 5.0HO - Idle issue - Seeking advice


New Member
Oct 30, 2017
Posting here today to hopefully figure out dafuq is going on with my mustang. 94' 5.0HO.

List of new parts & adjustments.
- Plugs (.054)
- Coil
- Distributor (Adjusted timing to correct degree.)
- Wires
- Radiator & hoses
- Thermostat & Gasket
- Fuel Filter
- Bypassed Smog Pump

Car runs great 90% of the time. Sometimes, when coming to a stop, the idle will lower and raise like it's stumbling. If the motor gets stressed at all, it'll stall itself, or be close to it. The only thing I have left to replace is the fuel sending unit. (bad o ring.) Any help at all would be greatly appreciated.

1994 Mustang GT
Stock headers, offroad x pipe, with two flowmasters that are dumped.
Can't think of everything off the bat. Thank you for the help though.
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
polk county florida
Check fuel pressure, check for codes.
For idle/stall help our resident tool (jrichker) here has developed (he may have had help from others, not sure) a surging idle checklist, it can be found here:
Read it through then roll up your sleeves and start at the top and work your way through, don't skip around, it will help you find and fix things without wasting time and money.
In the tech forum you will find a technical/how to section that has lots of stuff of interest for swapping and modifying our cars.
Welcome to stangnet.


StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
Dublin GA
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.