Maybe this will help someone else. A while ago my 1990 Cheyenne, 2500 developed a problem where it would start right up normally, then loose power after about 30 seconds and stall. It would then start up fine immediatly after and do the same thing.
Tried all of the obvious things (ign module, fuel filter, check for error codes) but no luck. Since the injectors were wet with gas I did not think I had a fuel problem. Turns out I did. Insufficient fuel pressure. The fuel pump was fine BUT there is a very soft, short rubber hose that ties the fuel pump to the steel lines in the gas tank. That small hose had a tiny tear in it. Closer inspection showed this hose had disintegrated from the inside out. Probably from methanol.
The only way to make sure you have good fuel pressure (9-13 PSI on the inlet to the TBI regulator) is to put a "T" and gauge in the line. These can be bought ($40+) or do what I did and make one from an old fuel filter. I soldered a 1/4" piece of copper pipe in the side of the old filter and connected it to a pressure gauge. Didn't look great but it works, and fits right in the fuel line. Steve