1986 Bronco II won't turn over

I have an 86 Bronco II - I sat for a long time without being run.  At first it was fine then one day it died & would not consistantly start after that.  Since then we have put in a new fuel pump & replace fuel filter and housing unit.  Installed new starter.  New soenoid & battery.  When it dies after being driven it is usually after you get a hard jerking in 1st gear.  Not sure where to go from here.  Seen on sites that we should try checking spark plugs & wires???

You saying the truck won't turn over. That means the starter will not engage and spin the engine.  Is that the issue or is the engine spinning and will not start?

Or is the issue that it starts but stalls?

It will start on occasion but when it is started it will die for some reason and usually will not restart.

You need to determine if the problem is ignition or fuel related. Try a simple test when it won't start.

Do you have fuel pressure at the fuel rail? (FI)    Does the carb squirt fuel when the throttle is pressed? (carb)

Yes= fuel delivery ok

no= bad fuel pump, clogged screen at the tank

Hook a test light between the (+) and (-) terminals of the ignition coil.  Crank the engine and watch for the light to flash.

Light flashing= primary ignition components are OK . Check the coil for high voltage output by disconnecting a plug wire and holding it close to a ground. Have someone crank the engine and watch for spark. ( use caution. The spark is high voltage and be clear of any belts or the fan.) 

If you have spark the coil is ok.  

No spark= possible bad coil.

These are simple preliminary tests. to determine what system may be at fault. Do the diagnosis and get back with the results.

Good Luck

Light doesn't flash= primary ignition is malfunctioning.  ( most times the problem is the ign, module)  however wiring and pick up coil in the dist could be at fault.