1990 Suburban won't start

[screwballl]

I had this same issue on my 91 R2500 with 454
I also replaced the intank fuel pump first... then had a Chevy tech tell me it was likely one of 2 things
1) Distributor module (also had a new one that was bad from the beginning)
2) fuel pump wiring harness in the tank itself

since I had the tank dropped I replaced the wiring harness which did not fix it... as soon as I replaced the distributor module a second time with proper heatsink paste underneath it it worked perfectly... no problems since

hope this may help some

[higeye]

It was running fine 3 days ago! I went to start it yesterday and it just kept cranking! I didn't hear the fuel pump going so I installed a new pump relay. After not hearing the pump run, I installed a new pump & sock/filter. I also installed a new fuel filter. Now I hear the pump running but It still would not start! I checked the TBI nozzles and they were pulsing fuel when cranking. I checked for spark on #1 spark plug and it has good spark. I checked distributor cap & rotor-They both look good! While I was at it I replaced the ignition module also. I'm getting fuel sprayed at the TBI nozzles and good spark, but, won't hit a lick! ANY IDEAS???

A little history: 203,000 miles on the 454 now. I replaced timing chain 2 years ago with Cloyes true roller chain and sprockets set. Did a valve job and installed new cap & rotor with new spark plugs & wires at the same time. It has run better than I can remember than when it was new-Until NOW!