94 ford explorer intermittent start?

Okay so my 1994 ford explorer will crank but not start unless I have a battery charger on and press the gas peddle, I also have to keep applying pressure on the pedal to get the truck to keep running and it will idle from 600rpm to 1500rpms evendors die sometimes when i let off gas. I have replaced crankshaft position sensor, throttle sensor, maf sensor, ignition switch, fuel pump, ignition coil, eec and fuel pump relays, fuel filter, alternator and battery to no avail. I have checked gas pressure at Schrader valve, voltage on injectors, spark in wires and grounds from power relay box and solenoid also starter. I was told by my mechanic to check all grounds but I'm unable to find a wiring diagram. Any help would be very appreciative as I don't want to just keep throwing money at it. I'm almost possitive there's a short somewhere.

If you don't want to keep throwing money at it, why have you thrown enough at it already to REPLACE the car? Do what you SHOULD have done in the first place, and take it to a COMPETENT mechanic (not the one that told you to keep GUESSING), and have them DIAGNOSE the problem. I'm completely positive YOU will never find the problem.

Thanks for the vote of confidence Steve F. Some parts where purchased others i have taken off of my 93 explorer. It did however start, again and again no problems so I did a koer test throws codes 111 and 211. 111 everything fine, 211 is pip faulty. I'm now going throw the wires from pcm, cam and crank sensors. I know it is a ground or wire short. Is there some voltmeter tests I can run to verify connections and grounds to these parts? Also I just went out and it won't start now.