ill try these tomorrow and see what happens. my fuel pressure gauge says 6.5 psi under the hood but ill try a different fuel source. ill get the meter out and test everything i can.
I think that's pretty good, actually. I agree that it's a good idea to test an alternate location just for repeatability, but I wouldn't be surprised if it was fruitless because you've got ample fuel pressure. Just trying to be practical and expedient, not negative. I would definitely consider carb metering, and I definitely agree that spraying a combustible aerosol like starting fluid and seeing if you get better results would, in conjunction with good fuel pressure and a newly cleaned carburetor, point a great deal at the carburetor's fuel metering capability. There's a good video on YouTube of how to test an HEI ignition coil with a multimeter that I've used. I found that my original one had these dead spots in it, and I tested an old factory coil that I had laying around that did the same thing except worse, and then I went to the parts store and tested a new one. It did no such thing. It's only a small piece that makes contact with the conductive surface on the coil so I went ahead and replaced it just to be safe. The parts stores will test the ignition control module for you, also, if you want. The spontaneity of your issue makes me secondarily suspect it simply because that's how ICM problems usually are. The reason I don't primarily suspect it is because you can start the truck and run it for a moment, where ICM failures usually disallow any successful starting after failure or wait until the motor gets warm and fail until it cools back down again. Ignition Control Module problems can do weird things sometimes, and it's best to keep an open mind so I don't confine the potential diagnosis to the textbook on that one. Oh, and I'm sure you have a lot better clearance to look at fuel spray than I did in my B body, but I got my phone and turned on video with the flashlight and watched the fuel spray on the phone instead of trying to cram my face down in there. I even recorded it so I could watch it later if I had second thoughts. Make sure all your vacuum lines are together and not broken, disconnected, or unplugged. I'd actually check up on the EGR if you still have it. EGR problems can really hinder or even stop a car from working. If it's the old, open factory style with an accessible plunger, you can depress the plunger, cap your finger over the nipple, and see if it stays up. If it stays up and only comes down when you remove your finger, the EGR's fine. If it comes back down, you have a nice vacuum leak right there. If it's a newer, sealed type EGR valve, you can unplug the vacuum and plug up both sides and see if it starts and runs better or at all. I've had a bad EGR valve happen twice to me. On TBI, it made the truck run horribly and die very soon after. On the E4ME Quadrajet, it was leaking vacuum around the plunger and just made for a shittier run. Other vacuum leak sources are the innumerable factory smog provisions (if you still have them), especially those closest to heat sources, plugs and caps, especially the homemade variety,
to disable factory smog provisions (if you have that instead), primary throttle shaft area on Q-Jet (the throttle shaft will rock around instead of staying still when you try to move it around), carburetor base gasket, and worst case scenario, the front and rear lip area of the lifter valley on the intake manifold gasket. Brakleen, WD40, or starting fluid sprayed in all those places can test for vacuum leaks, with an increase in idle speed being indicative of one. That's an auditory test. A visual test would be to get a smoke machine, if you have access to one ($$$) or a cheap cigar to blow through the vacuum lines where they plug into the carb and watch where the smoke wofts up from. I doubt a massive, spontaneous vacuum leak is your problem, but they sure don't help. Just a few vacuum leaks could subtract three to five inches of Mercury of vacuum at idle, and I had about eight or nine vacuum leaks on my Caprice when I first got it so go figure how it ran until I hunted them down and fixed them. Inspect your ground ends, ground sites, and your ground wires. Very important and often overlooked, I'd say. I don't think your instrument light problem is related to the issue. You clearly have enough voltage to spin the starter enough to start the truck, even if it's for a second. Sorry for the long windedness. I'm just trying to blitz anything I can think of so you can get it going back ASAP.
