when all else fails i always fall back on this little trick i picked up on the job,(i'm a heavy equipment mech.) You can get a clean rag, at least a 18inch by 18 inch square or larger and pour clean regular gas on the rag, you want to saturate it then lay the rag,(wadded up in a lump,) over the intake screen and have someone crank it for you, you will have to control the throttle from under the hood, after it hits and starts rev it up with thr rag still on the intake , let it run for a few seconds 30 or so, use your own judgement,it will blow white smoke but this is norm. then remove rag and truck should level off if not repeat but wait a few min. inbeteen times .make sure to re-soak rag with gasoline. hope this helps....
Bob.....