I just finished installing a 408 Stroker in my C3. But, I haven't been able to get it to run. The tune is good, infact it will run for 5-10 seconds. But it is only firing on 2,3,5,8.

The cam and crank sensors are plugged in and the wires are not damaged. Atleast none that I have been able to find. There is no spark from the coil. The coils have been swapped and the problem does not follow the coils. I also checked the wires from the PCM and they are good.

What else can I check? I don't think it is the cam or crank sesnors, because it wouldn't fire any cylinder if they were the problem. same thing with security.

 

No to be a smart ***, but did you plug in the main harness to the coil pack distibutor plug?? I know it sounds lame but it sounds like thats what it is since its the entire side and not just a couple here, and a couple on the other side.

 

Woops sorry i miss read that, nvm you have a much bigger problem than that lol. I was thinking it was one entire side that was not firing at first, now I see you have 2 on each side not firing. Are you positive that the coils arent firing, and that its not just bad sparkplug wires?? If so then im at a total loss unless you also happened to do an Injector swap that involved you splicing the wires on the harness to mate to the connectors on the injector!!

 

Yeah, We used an ignition tester. They are for sure not firing. And, I have tried new plugs and wires just to be sure.

I may see if I can get another PCM. I can't think of anything else.

 

Update. I'm still looking for any input you guys have.

We have swapped PCMs, sensors, checked all wires, grounds are all on, relays swapped, fuses checked.

No real update other than that. The GM tech that was helping me has given up and I can't think of anything else to try. I checked with the builder and he assured me it has the right reluctor.

Please help before I shoot myself.

 

if the motor is the only difference from before then i would say reluctor wheel

 

That's what I'm worried about. But I don't know how the 56 tooth would react. My thoughts are that it would just make everything happen more often. So, extra spark, fuel etc. But i'm not sure on this though.

 

not if the pcm doesn't recognize the pattern. but it also seems like it would code something.

 

did your builder swap reluctor rings??? because thinking about it it sounds like the ring is clocked wrong, i'd actually be willing to bet money that either it's the wrong ring or more likely clocked wrong. what crank is it???

 

It's an eagle 4" stroke crank. All new motor. I am going to pick up a 5.3l froma friend next week and see if it fires. If so, then I know the problem is with the motor.