I have a 2001 F150 4x4 4.2l w/ 114,000 miles on it. Within the last week my truck has had trouble starting. The first 2 times it would just turn but wouldn't turn over and start. I pulled the key out and tried it a few more times then waited 5 minutes and then it started up. The past 2 times I turn the key and it almost starts up and runs very rough for about a second and then kills over. I've had to let it sit for over an hour but then sure enough it started up. I've disconnected and reconnected the battery and there also isn't any codes.

I'm thinking it might be the ignition starter switch? Am I on the right path or could it be something else?
Thanks in advance guys!

 

Have you ever changed the spark plugs and wires? Have you ever changed the fuel filter?

 

Im thinking you need a good tune up along with some preventive maintenance ........

 

What I get from your discription is the motor is flooding with fuel due to no/poor ignition.
The rough running, the wait for starting.
To get a further indication, floor the gas pedal while cranking.
If it starts easier, it's a flooding issue.
Flooring shuts off fuel injection and clears the cylinders.
Good luck.

 

Changed both plugs and wires ~4,000 miles ago and fuel filter ~3,000 miles ago. I keep up on all needed maintenance and run BG 44k Fuel Injector cleaner through it once every other month.

 

Have you checked the fuel pressure yet? I'm thinking that its your pump...

 

My guess is the IAC, Idle Air Control, on the intake. Yours being a 4.2 also, I'd look at the IMRC which causes similar problems, not as bad but the v-6 is prone to this. Next I'd check out the crank positioning sensor. Check these before ignition because that is not just a switch, it's a new PATS system, and a reprogram too.

 

fuel pump

 

After key on, you will always hear the pump pressurize the lines. So what to listen for, is for the pump NOT to pressurize the lines after Key On.

Leave the key in the on position when this happens. Pop the hood and touch the relay. If it's warm or hot, that is the problem.

If the relay is okay, with the key still to run, strike the tank with a hammer, about right in the middle. If it's the pump, it will usually kick in after you hit it.