Engine will not restart when hot

Daveztoy · Jun 30, 2014

I have been struggling with this problem for a while and hope maybe you guys could help me out. I have a 95 mustang GT, pretty much stock except for some cosmetic upgrades.

The problem I am having is this. When the engine is cold it starts perfect. I can drive it without a problem. If I then turn the engine off (i.e. to fill up with gas) it cranks over ok and revs to the usual 1k - 2k RPM and then the RPMs drop off and the engine dies and shuts off. If I keep the gas pressed to keep the RPMs passed 2k for 5min or wait 40min it sorts it's self out and I can continue driving.

I have taken it to 2 different mechanics and has been in the shop for about 6 weeks and they can't figure out what is wrong with the car. I had the computer taken out and scanned and no problem found. Was convinced it was the distributor and replaced it.

Does anyone have any ideas or have seen anything like this before. I am desperate for an answer.

kaveman · Jun 30, 2014

Never had this problem before but I'll give you the best help I can.

Here is a troubleshoot method for ya courtesy of the Haynes repair manual.

1. Check air filter for dirtiness.
2. Fuel not reaching the fuel injection. Check for vapor lock situation
brought about by clogged fuel tank vent lines.
3. Bad engine ground connection.
4. Defective pick-up coil in distributor.
5. Fuel injection or engine control systems malfunction.

Hope this helps and good luck man!

kaveman · Jun 30, 2014

Oh and here is another set of troubleshooting methods (the first set was for "engine hard to start while hot" this is for "stalling engine")

1. Idle speed incorrect
2. Fuel filter clogged or water in fuel system
3. Damaged or wet distributor cap and wires (probably ruled out by your distributor work)
4. Faulty emissions system components.
5. Faulty/incorrectly gapped spark plugs.
6. Spark plug wires.
7. Vacuum leak at the intake manifold or vacuum hoses. (When I first installed my CAI I did have a problem with it falling apart right after the MAF sensor that caused the engine to stall when the RPMs dropped at stop signs and whatnot.)

CC'S95GT · Jul 1, 2014

Sounds like a typical dizzy issue. Did you replace the distributor with a remanned or new? Remanned dizzy's are hit/miss as far a reliablity.
Have you pulled codes?
How many miles on the car? Cats could be clogged.

iamtheshaner · Jul 1, 2014

Has this other shop replaced anything? Start/stalls are often IAC motor related especially when it's hot. If you can keep it running with your foot on the accelerator, the reason it wont run is because it's not getting enough air - throttle will have nothing to do with ignition nor will it correct some sort of vapor lock or airbox restriction. It's always good to look over the basics but I'm going to assume the shop did this otherwise they aren't much of a shop.

Depending on your skill/resource level I'd recommend you take it to a better shop; perhaps a reputable dealership