I have a 92 F150 with the 5.0.
I recently installed new plugs and wires after which the truck ran fine.
After sitting for a week,the next time I drove it, it ran like it was only hitting on half the cylinders.
All plug connections are fine.
When I crank it up, it will rev up for a sec then idle down and die, but will eventually crank and stay running.
Will the throttle control sensor cause all this missing? Its got a code for it.

I went through all 15 pages of this area looking for a thread with similar problems.

 

Does anybody have an idea about this?

 

nope i have the same truck and never had that problem..i have let mine sit up for like 3 weeks

 

Could be something sticking in your throttle body? Since you have the same truck as mine, take a look at your exhaust manifolds - are they cracked? Both of mine were when I bought it.

Mine started to run like crap after doing plugs etc too, and it started to run really hot. It could have been something to do with the cracks, but I was getting an O2 sensor code - replaced the O2 sensor and it went away, I replaced the manifolds and it's running pretty well now. I do plan to service the throttle body, though.

You could try running Seafoam through it, cleaning up gunk may help.

I suppose you could consider whether your fuel's contaminated. If you have two tanks, try changing over.

 

What plugs did you use when you changed? People reporting problems after switching to non-Motorcraft plugs are commonplace here. Ford motors just don't like other plugs.

 

Maybe try another type of spark plug? Do you have power to all of the other accessories ( radio, windows... ) if not it could be a weak battery or alternator problem.

I put NGKs in my '01 5.4L to avoid any spark plug issues, and if anything they improved power a little