My 4.0 ranger just developed a problem that I can't quite pin down by reading old posts. When I start it up it starts and idles fine but will die if given any throttle. I can let it warm up for a couple of minutes and then it does fine or if I continously pump the accelerator to keep the RPM up around 4000 for about 30 seconds it will then operate fine. If I have to stop and let it sit for three or four hours, I have to go through the procedure again. wondering if it could
be the idle control solenoid or the mass air valve. All the vaccum lines look good. It runs great after the initial warmup. By cold start I am talking about nighttime lows in the 40s-50s.

John in Fla

 

Lots of possibilities & the two you mentioned likely deserve a spot on your suspect list.
If you have a CEL lit, most autoparts stores will scan the computer for trouble codes at no cost, then post All code Numbers, as they can offer up good trouble shooting clues.
Don't begin throwing parts at the problem until you have a positive trouble shooting result.
Some thoughts for pondering, let us know what you find.