99 gmc sub won't start, engine turns.

The suburban was running good. Turned it off in the driveway. Ran in the house to grab something. Came back out and it would not start. It cranks good. Security light is not on. Oil pressure goes up when cranking. I replaced fuel filter, bled the air out of the lines. Checked the pressure at the top of the engine (5.7 vortec). The fuel pump can be heard when switch turned. I replaced the plug wires. Checked all of the fuses. There is constant power going to the injectors. I even tried spraying WD-40 into the throttle body to try to get it to fire (Yeah I know its dangerous). I removed sparkplug and held the threads to the engine block while cranking. There is fire on the plug. Any suggestions?

hey I'm having the same problem if you find out what it was please e-mail me and tell me what you found. As for me I have 96 suburban and wife went into the docotors office came back out to go home and NOTHING.. AAA came over to tow it and 1st words he said was FUEL PUMP.. so I replaced fuel pump, screen, fuel filter f nd guesswhat NOTHING still the same.. So we dropped the tank again and took out the pump and primed it and yup it works so we put the pump back in the tanks hooked up the electical inputs and grounded it to see if the pump would shoot out fuel and yup you guess it nothing happened. well the relay was replaced and power at the box for the relay BUT the gray wire from the box to the connection must be broken because there is no power we tested with a test light. well if you fiqure out your problem could you e-mail me at drewmgd73@yahoo.com and tell me what you did and 11-19-04 I'll be working on this pain in the butt tonight wife is getting very UPSET with this we only had it for 2-weeks...

Thank you
Andy

It was the fuel pump. During the proccess of troubleshooting, I did not recheck the pump to see if it was coming on. It was about 65 degrees when I was working on it, and the heat pressurized the lines enough to make me think there was some pressure. Before resorting to having it towed to a mechanic, I thought I would check the fuel pump once more, sure enough, it did not come on. It is now replaced and running well.

Note: make sure your parts supplier gives you the right one. I would suggest putting AC Delco back on. It has a 3 letter code on top that identifies it. A Chevrolet dealer can look it up by the last 8 digits of your VIN.