fiddle

i have a gmc k1500 5.7. cylinders 1-3-5-7 have fire, and 2-4-6-8, do not! what the hell, and why.

Gundog

When you are testing 2,4,6,8 you are using a different ground area,I believe that is your issue. It is also possible that the routing of the plug has caused them to burn. try switching out the wires for new ones. Good luck.

fiddle

1993 gms k1500 5.7 timing is correct, wires are correct, fire in all wires, blue fire from coil, all fuses are good, 2 grounds on the motor. all sensors are new, battery is new, tbi is rebuilt and both spray. this is a complete rebuild from bottom to top. the code reader pulled no codes. The truck did start after rebuild, it ran for about 20 min. but now it rotates and fires and it tries, but it just won't start. So I threw money at it and replaced cap, rotor, wires, coil and plugs, and ign. module. It does have a deep back fire, but not a loud backfire like 180 out. I checked timing again and it's still dead on. I am really open to suggestion.

Allan In NE

Let's clearify.

Do you mean that there is no 'spark' on the right bank or that it just won't 'hit' on any of the right bank cylinders?

Allan

fiddle

I have spark in all the wires. the motor just rotates and tries to start but it just won't.

Allan In NE

Okay,

It's really an art to adjust new 'empty' lifters. Now that they are full of oil, just betcha that they are too darned tight and they are holding the valves open.

Back the right bank lifters off a half a turn and see if it starts and runs. If so, get 'er warmed up good and re-adjust all.

Allan

79chevyman

y its bakcfiring is because you have to much back pressure from the valves bein held wide open

fiddle

That was it brother. I loosened those lifters and she fired right up. I sure am grateful for your help. Now I'm going out to readjust those lifters. thanks a bunch.