1995 f 150 won't start when hot
 

Working on a 1995 f 150 with a 302 that has fuel and spark and cranks fine but won't start when the engine is warm. Let it sit for 1 hour and it will start and run fine till you shut it off and it won't start again.It has good spark so it doesn't appear to be a coil or pick up but if I'm wrong please let me know. Acts like a vapor lock but I haven't seen this happen in years. Not after fuel injection.
If anyone has had this or anything that you would check that I haven't please let me know.

Thanks Rick

my truck did the same thing. but it does start, but really hard to start... my trucks egr is stuck closed though. dunno if that effects it. pull koer codes from your truck see what it gives you.

Sounds like your starter is afraid of heat!

Does this vehicle have aftermarket exhaust manifolds/headers? Big block chevys have this problem too. The radiant heat from the manifolds cooks the starter. Truck will not fire back up until the motor cools off.

Make sure your exhaust heat is avoiding your starter. You might consider installing some sort of heat shield around your starter and/or manifolds. Or find a more robust starter....

Hope this helps

Mike

Starter isn't the problem. It cranks over fine. Has plenty of speed. I will check the EGR valve and see if it is stuck but it has no light on and runs fine when it's running so i'm not sure this is it but it is easy to check.

Rick

Make sure your battery cables are ok all the way to the starter...heat can affect those too.

If your truck only starts when its cold, it could be. I've seen this before on my Fish and Wildlife chevy trucks.

Yea, when the starter is cool. Again, don't discount the starter just because it works cold. I have a faint suspicion the heat associated with the truck warming up is the reason you can't fire it up warm.

Again...make sure your starter isn't cooking. Or the terminal from the battery to the starter is solid.

think it's mabey in the fuel pump? i have a 94 taurus 3.0 and lately it quits on hot days, put in a gallon of gas from the jerry can and it starts right up. i've been told it's the diaphram in the fuel pump's getting weak, and the hot gasoline amplify's the problem, then the cool gas i put in cools it. anyone else heard of this? neighbor's 91 chev 1ton has a tbi 454 and he said it did the same thing before putting in a new pump. i dunno.

check the coolent temp sensour.

Thanks for thr ideas.. The cables and the starter are ok, It cranks the same cold as it does hot... Adding fuel doesn't help either.(willing to try anything) Haven't got to the temp sending unit yet but thats next on the list. Anymore ideas please let me know and i will check them also.

Thanks Rick

I had this happen on one of my work trucks. Took it into the dealer to have it fixed under warranty, and they said it was the fuel pressure regulator.
But this was a 99 chevy truck. Don't know if a Ford would do the same

Everyone else is throwing in their two cents, heres mine. I don't know where the coil is on a 302 but mine is next to the block. Could be a weak coil getting hot.

I second the weak coil theory as a good place to start when you have a heat up won't start and have good crank from the starter.

It DEFINATELY isn't caused by an EGR being stuck closed, the EGR is supposed to be closed when starting.

Have you ever pulled one of the plugs out when it throws this fit to see if it is wet with fuel or not? If you are sure you have good fire during this time then it almost has to be coming from the fuel system. A quick fuel pressure check during this could also be useful since on a fuel injection system can have fuel pressure and still not fire the injectors. The fuel pressure check will tell you if it is the pump or not also. I think one of the guys on here said once that it should carry 30# of pressure just turning on the key, not running. Not knowing exactly what the computer is looking at to start the engine that is about all I know of to look at right now. Does anyone know if there is a delay in the system looking for oil pressure? When the oil is hot it doesn't have as much oil pressure.

Hi, Next time it does, hit it with immedatly with starter fluid . If it starts its a fuel issue.if it dont, its spark related .Then I would have the module tested .Pat