Chevrolet Repair: 98 GMC will not start, check fuel, starter fluid

Question
I have a 98 GMC 5.7 that will not start. This is the third time this has happened. the first two times were in the morning and after a few days it started with no problem and ran fine and started every time for a few days. this last time it has been about a week and I try about every day and nothing. I have checked and have spark at the plugs, I've checked for corrosion at the dist. cap, none, and I've tried starter fluid and gas in the intake and nothing. It does seem to backfire when I tried to start it, it has done that every time it has not started. The check engine light has not come on. Any help would be appreciated.

Answer
Hi John. check fuel pressure, if ok then pull plugs dri them off and reinstall, hold gas pedal to the floor and start. or you can disconect the wiring for the inj to help clear flood. if you get it running let it warm up and then change oil as the excess fuel in the oil will send the 02 sensor out of wack. hope this helps