Hey there, I think i already have an idea on what is wrong, I read a couple of the posts here and have come to the conclusion that it's the starter/solinoid.
but just to describe it, to confirm this.
Just recently has it started, but when I put the key in and turn it , all I get is a whirring sound, and at first my father said it was the cap/rotor, and i though it was, because the whirring sound sounded like it was coming from right behind the firewall where the cap/rotor was.
But as of last night, my brother in law crawled under my truck and gave the starter a couple good taps , though the truck still didn't start, but i kept at it for another 10 minutes and it finally started.
I just tried this morning for 30 minutes to start, and at one point it almost started, but the battery choked from the constant cranking and the truck started to make the whirring sound again.
I'm in desperate need of a good answer and fix fast, becasue I'm going to have to take my 2nd day off in a row from my job to fix it, and they aren't happy about the first one.

It would be GREATLY APPRECIATED if you started posting very fast, my job might be in the balance of this stupid problem.

 

year make model engine 4 wheel 2 wheel drive does the engine turn over the whole time and just not start? i dont understand how the starter not enguaging could run the battery down after 10 min unless it was spinning the engine over. Slow down and explain and we will try to help ya out

 

Is the "whirring" sound coming from the starter? If so, I would think the bendix in the starter is no longer engaging on to the flywheel/ring gear. Probably needs a starter. I am no expert, but I don't think the solenoid will help this. You said you "tapped" the starter, try hitting it harder. Please note, that if this helps it is probably only a one time fix and the starter will need to be replaced.

 

If the engine isturning over andyou are getting wires chatter. When it gets dark have some look under the hood to see if there is any blue spark. But if if will not start it mightnot eitherI'm not for sure. Just make sure that the wires are not loose or broken.

 

Mine did the same thing and it was the starter. I picked up a rebuilt for $40, so if you can find one for the same price then it's worth a shot. It's a huge pain in the *** if you've never replaced one of these starters, but it's worth it if it gets fixed.