i have a 1988 F-150 with a 4.9 and my problem is when after it gets hot and you turn it off it doesn't want to start. It's like when your batterie is low and just barly turns over the starter. It's not the starter it is bran new It would be nice if some one could shed some light on this for me.

 

Even brand new parts can be bad, especially if you get them from places like Autozone. It would have both the battery and starter tested out of the vehicle. If those come back fine, it might be the blower fan. In '87 - '89, there was a blower than cools the fuel injectors. It should switch on a couple minutes after the motor is shut off on hot days and run for maybe 10 minutes. If it's not working, it could be contributing to the problem. Also consider replacing the battery cables on a truck that old. They get abused pretty bad and can corrode from the inside out. They'll look fine from the outside, but they won't conduct enough electricity to start the truck sometimes.

 

check engine ground strap or straps. new parts do go bad. does it start with a jump?

 

it will start with a jump. it just draws too many amps for the batterie to handle. where is the blower fan located? is it by the batterie and about an inch thick.

 

then you need to find and check and clean engine grounds. this was what was wrong with a ford i fixed.

 

You might want to load-test the battery. It takes more to turn over a warm engine.

Another thought is ignition base timing too advanced.

 

where is that located? I have been having the same problem as the original poster for about a year now on my 87 150.
Mine won't start with a jump..it has to cool for 30 minutes or so..then starts normally.
perhaps that blower fan is my problem, God knows I've changed everything else, so I'll give it a shot

 

I'm curious too. Never heard that before.

 

I just fixed the same problem on my 89 f150 w/ 302.

I changed the starter, which I knew was about sot.
I had the alternator tested - was bad and I changed that.

Still had the problem.
I added an additional ground strap from the battery negative to the engine for a better ground. Still not fixed.

I cleaned all of the contacts on the starter relay.
Guess what? The ground to the starter relay ( the small push-on wire was almost broken.

I crimped a lug onto it and bolted it to the terminal.

Problem solved. I hope your fix is cheaper than mine!

 

you could also run a new wire from the starter relay on the fire wall to the starter sol. ford is famous for that wire going bad . if you cut the end off you will find some thing like battery acid building up inside the wire. i also use a heavyer gauge" number 8 or 10" wire from a marine store that is tined inside to help stop the problem.

 

The reason I came to this board was a problem just like this. It (as posted above) was the engine to chassis ground. Turned one 9/16" nut and Presto, problem solved. Make sure all the flat braided grounds from engine to chassis are secure.

 

Tex, if thats the culprit, wouldn't it do it on cold starts too?
at this point, I'm up for any ideas. This damn thing has stranded me for the last time.

 

the first time i had a bad ground was with a lincoln continental. it was my dad's and he kept getting stranded in it so he bought another car. in the middle of winter i needed a car, snow was up to the top of the door on the lincoln, and i bet my dad i could get it to start. he said it was mine if i could get it going. took my friends jeep with heavy cables to get it going but the lincoln was mine. got used to driving around and timing the cool down so i didn't get stuck to much, but one dark night when it did not start i hooked up a battery charger and in the dark saw a spark at loose engine ground. tightened her up and never had the problem again. now i always look for this problem first. glad i could help and hope everyone liked the story.

 

when everything is hot it has more resistance and draws more current.

 

quicklook2 is right on. Heat increases resistance and requires more ampherage to overcome. In my case the ground was completely loose. Cold, turn the key and off we go, after running for 5 minutes, nothing.