I got lucky and just found the problem on my 1989 Chevy G20 Van. The van would die every now and then in the past but this time it quit all together. I was pulling my other van into my yard and bumped the bumper on the Chevy G20. The next day it wouldn't start at all.
The problem I found was very similar to yours. I took the lines off the carberuetor and they had plenty of fuel but nothing was coming from my Injectors. I cleaned the Carb and the engine ran when I primed the Carb with Carb cleaner.
I used a test light to confirm that I did have power to the injectors. I tested all the fuses in the fusebox and the last three on the left (horn, parking lights, ECM1) didn't have any power when they are supposed to be hot with key on.
I inspected the outside of the loom where it goes into the firewall and connects to the fusebox and it looked really dry and old so I decided to inspect it.
I took it apart and gently pulled on the wires and low and behold three of them (one red power wire, a tan with white stripe, and a solid white wire) came out of the block with ease. I guess when I bumped bumpers it broke the wires off the tabs all the way.
I traced the wires to the correct spaces on the fusebox, drilled a hole in the firewall and wirenutted and taped them together, put the fuseblock back together and fired her right up! I hope this helps.
Seems like I have read quite afew posts from people with around the same year chevy with no fuel getting past the Injectors.
Sunday, June 8th, 2008 AT 9:23 PM
