Why won't my truck start?

[gamtboy]

1996 ford f150 will not start if it has been running or started a couple of times. Just happened Friday. Tried to start it and starter would not engage. Would not jump off with cables. Replaced starter and it started right up. Turned it off and it would not start again (even with jumper cables) for about 30 minutes. Finally started and I drove it 100 miles home and it runs fine once started. I decided to also change the battery, but still have the same problem. Will start if it has been sitting for a while, but will not start up right after being turned off.
I cleaned and changed all the battery connections and I replaced the selenoid. It is an automatic, so I will try to start it in nuetral. Maybe my ingnition switch?
No carborator, fuel injected. I did change the selenoid. Also, I am thinking it could be the starter wire.

Also, before changing the selenoid, tried to jump it from there and it would not.

[JohnC]

Sounds like a vapor lock, try to wrap aluminum foil around the fuel line going into the Carb.

[Griz]

It could be the result of a worn coldstart plunger shaft on the carb. This causes fuel to drain off and there is no fuel left to facilitate the start. It would have to be really worn to prevent a warm start.

[kpowell101986]

This sounds a lot like a solenoid. There is usually on in the engine compartment. It is usually black and costs only 3-10 bucks depending on the one. Follow the positive cable from the battery, usually go strait to the solenoid. On both my cars it is located on the inside fender on the driver side. It will have the black box and 3-4 posts comming out of it. To install remove all the cables on the solenoid itself, note the way they are connected to it. Unbolt the old solenoid and rebolt the new one. Reinstall wires and you're done. This is the first repair I would try in your situation.

[DW]

check your grounds first and your battery contacts to be clean of that white,then it is 1 of 3 or 4 switches if auto hold your shift in neutral key in start move shift almost to the gear pos if cranks neutral switch,if stick try stomp on clutch or short out the siliniode on fire wall

[boogyon]

the pos cable goes to the starter solonoid thats what is sticking also you can jump it from their.