99 5.3 Sierra 4x4 NO SPARK???
 

This has everyone stumped... We were driving the truck down the road and it sputtered and shut off. Pulled over it started up and drove another 100 miles till it did it again. Finally got it running again and got it off an exit a few miles down and it has not started up since. Checked ignition relay, fuel pump 60psi at the rail, security light shuts off when door is closed, dumped fuel down the intake still would not fire, had 3 codes for crank position sensor so we replaced the CPS and cleared the codes but it still WILL NOT START :confused:. Even after continuing to try to start it there are still no codes and NO SPARK on any cyls. There is fuel but NO SPARK. Any help would be greatly appreciated, codes were checked with a GM Tech II :confused::confused::confused::confused:

check the wires?

the wires are new and there is no way all 8 went bad at once.....

Well.......lets start simple.....check your power to the coil...make sure you have it...if you do try a different coil......used is ok as long as it works....also check your grounds, it sounds like you have lost power............its a simple process of elimination...start obvious and work backwards....hope this helps

It cannot be a coil, the truck is distributor less and has 8 coils. It is a new body style 5.3 1999.5 so there is no way all 8 coils went bad at once. thanks any way...

anyone have an idea?

May need crank re-learn with the new sensor.

I have the GM tech II computer and a full battery. How do i do the crank sensor re-learn?:confused:

i meant crank sensor wires lol

With the tech 2 did you check for codes in the bcm for theft codes? If none does the tech 2 display crank rpm when trying to start in data list of pcm? If you dont have crank rpm on the tech 2 check for battery voltage at crank and cam sensors. Seen wires by the ac belt tensioner area at the front of the engine get chaffed by the centerlink of steering? Truck needs to run to do crank relearn. Under special functions of pcm in tech 2.

a friend of mine told me to check for voltage at the CPS also last night. Thanks will do!