When I fuel Pickup there are surges of engine including engine shuts off esp.at lower speeds; I place shift in neutral start up and give engine 3/4 throttle, at Hwy speeds not so much,whenever fuel level is 3/4 or lower problem goes away this is a 4.0 engine--my other vehicle 2002 ford Explorer 4.0 eng has the same problem:

Thanks

 

How many miles? both on the vehicles and spark plugs.

 

Check engine light on? Any codes?

 

17000 miles on pick up-new spark plugs and spark plug wires-there are no codes,no caution lights ford dealer replaced distributer: I replaced fuel filter: nothing helped: My 2002 Explorer with 4.0 engine same problem, I quit using gas with Ethanol, didn't help: thanks

 

Seems odd if there are no codes.

If it was mine I would hook it up to an OBDII scanner that has live data and observe what is going on with the engines as you drive them. Probably most importantly, is the ECM operating on open loop at start up, then closed loop after about 20 seconds... or is there an open loop fault. Are your fuel trims around +/- 5% at idle and on the highway. And are all your oxygen sensors oscilating from high voltage (.8V) to low voltage (.1V) both at idle and on the highway.

You could also clean your MAF sensor with a can of MAF cleaner and you could check fuel pressure at the fuel rail. Clean your throttle plate with some throttle cleaner.