Its not a silverado but I could not find a scottsdale or C20 option. This old truck is not used much. Its not started much. It has always started hard when sitting for months. This time it would run very poor not getting much beyond a idle when it ran and would stall after 10-20 seconds. Now it will not even fire. It is getting gas. I unhooked the gas line at the carb and turned it over at it has gas coming out. I did not test the pressure but it should be enough to fire. I also have dumped gas down the carb. As for spark, with not one to help me the only one I could test was the one closest the the front with a spark tester and it had good spark. The others are in a spot that if I turn it over I cant see the tester. I would need someone there watching or maybe doing it in the dark. I assume if one has spark they all do. Vacuum lines are all hooked up and all of the cracked ones were replaced.
My thought was there is something wrong with the carb, needing cleaning or rebuild, but dumping gas down it should at least get it to fire shouldn’t it? It will not fire in the slightest.
At one time when it would at least start and run like crap as I attempted to start it gave a big backfire and had some flames came out of the carb, luckily the fire went out in a couple seconds. That may have been the last time it at least started. I don’t know if that means anything.