91frppgt

Hey guys, so I got my PCM back that's tuned correctly, the truck fires up. My mechanic put the cam, springs, and pushrods in. I'm 100% confident in his work, so I'm thinking it's not a mechanical problem. Anyways, on a cold start if I fire the truck up it idles for about 10 seconds then starts back firing through the driver bank. It's loud, louder than a shot gun! So i killed the truck, walked around and touched the passenger headers. They are really hot, can't even grab and hold on to them. Then I went to the driver side, they are warm, but not near as hot as the passenger side. I tried firing again, same thing almost immediately. So I took the valve covers off, re torqued all the rocker arms to 25 ft lbs, checked all my grounds. Im stumped. I don't have a way to pull DTC now, but my check engine light isn't on either. Anyone know what could be the issue? All of my sensors are hooked up. I don't have a air filter on the truck now, but I don't think that would cause the problem. The crank, 02 sensors, idle air control, tps and knock sensors are brand new. Only sensor that is old is the cam sensor.

91frppgt

I also swapped plugs today with the ngk tr55 plugs. The old plugs all smelled like gas and looked like they had been firing.

vinceI

iTrader: (5)

Is the wiring going to the coil packs on the drivers side bank mixed up?

91frppgt

No, I checked all the coil packs theirselfs and I checked the actual passenger and driver connections. Everything seems to be ok.

91frppgt

My harness didn't come labeled however, I'm just judging by how the harness itself is laid out. So if the passenger side connection was at the driver side, and vise versa would it still run like I'm talking about? It sounds like it's hitting on 8 cylinders now, but it may not be.

91frppgt

What I'm trying to say is, if I disconnect both passenger and driver coil harness, I can rotate them 180 degrees clockwise and plug them in that way. But if I disconnect the battery, and then try starting it how it sits, for 7-10 seconds it sounds like it's hitting on all cylinders then it starts backfiring through exhaust. Then I can kill it, and it will backfire randomly while cranking.

vinceI

iTrader: (5)

If you have factory colored wiring the main harness side of the coil wire connectors with 7 wires in them will have white stripes on the purple, blue, green and red wires on the even side. On the odd side they will be solid purple, blue, green, and red. That will tell you if the main harness is correct. then if you look at the 4 wire connector on each individual coil cylinder 1 will have a purple wire in it 3=blue 5=green 7=red on the odd side 2=red 4=green 6=blue 8=purple. make sure they are not mixed up, the small harness at the coils can be layed out the opposite way and be hooked up so that 1 is hooked on 7 and so forth.

DW SD

Did you decide to buy a different harness?

I PM'd you about a good resource.

Doug