I have a 1990 f250 5.8 that cranks fairly easy when cold but once it gets warm it sometimes dies when coming to a stop and won't crank back for a few minutes until it cools down a little. If I shut it off to run into a store it doesn't want to start back. It acts like the battery is weak and barely turns over. But once it cools off it starts easy. Anyone have an idea what's wrong?

 

There are 2 main possibilities.

1) corroded battery terminals or with the main battery ground to the chassis and engine. Take them off and wire brush the terminals and connectors, and then apply a coating of peterolium grease to everything before clamping it all back together, this will prevent further corrosion.

2) Engine is running rich which washes fuel off the cylinder walls making hot starts harder. Is the fuel milage particularly bad? Any codes present? Even if the check engine light isn't on codes can be set so check it out and fix anything that comes up. If the O2 sensor is old or of unknown age change it even if there aren't any codes for it.

 

had this issue with my 91, new starter fixed all my issues.

 

There is a very easy way to check the starter theory. If you have an amp probe type multimeter, check the current draw during the hot start and cold start. a considerable difference could tell you a few things. First, a possible bad starter, or even something else binding up when that particular component is heated causing the starter to strain and overwork itself to start.

 

I do not have access to any type of multimeter without buying one. I am beginning to wonder if the battery is the culprit. It is new but seems small for the truck and I think once the motor leaks compression slightly - 5-10 minutes - it will crank usually or when jumping it off it will crank. It seems if it was the starter it wouldn't cool off enough in that period of time to make a difference.

 

Same problem with my 89. Beat my head for days checking timing and a dozen other things.... Cold start no problem, run to a buddy's and get ready to leave, draggin begins. .....Couldn't believe it was the starter.

 

Had this same problem with my '89 5.8L. Replaced starter first - no joy. replaced the coil, that seemed to help, though it's still not 100% good. I talked recently to an old Ford mechanic who told me that it's the electronic module on the side of the distributor. I have it, but have not installed it. Waiting for weather to warm up a little.

 

Does yours die every now and then when coming to a stop or idling? Mine does. That seems to make sense to me if a module on the side of the distributor is bad. How much did the module cost?

 

Just throwing my 2 cents in here , but the last time I experienced anything like that, it was in my old 67 500 fastback it had a 302 and it was vapor locking. When it cooled down it would start and run, if I turned it off then it wouldn't restart until it cooled down.

 

Stalling and hard start may be two separate issues. As mentioned, check the wiring, especially the cable ends for corrosion. Also make sure none of the wiring going to the starter is routed near the exhaust. Heat increases resistance. The starter itself may be on its way out and the engine heat is increasing the resistance in the motor enough that it's to the point of barely working.

Try pulling codes to see if there are any stored.