Popping (like backfire) at high rpms (when loaded)

[keevinzanejohnson]

I changed my cp3 about two weeks ago and ever since the pickup runs but still is a little rough. To me it sounds like i have a bad injector. At low idle is has a little pinging sound and when you get on it at high rpms it will pop like a backfire when loaded. Can anyone help or just give me some advice. I need wheels!



03 3500 4dr dually, 5sp, predator prog. , intake, wicked diesel injection pump, 4 inch straight exhaust

 

[SRadke]

Sounds like low rail pressure. Do you have a gauge on it?

 

[cerberusiam]

It could be the Predator causing it, or, a lift pump, or, just running the rail dry.



Go back to stock and see if it still does it, then go from there checking pressures.

 

[keevinzanejohnson]

I will try it and see what happens on stock. And no I dont have a gauge on it.

 

[NRussell]

draining rail or blown hg. is it popping or fluttering?

 

[SRadke]

Mine made a weird WOT popping when I lost the head gasket. It was bubbling compression gas up through the coolant in the overflow bottle. Easy to rule that one out by removing the overflow tube at the radiator and taking a test run.

 

[TCDiesel]

The pinging may be related to injection, the popping is more likely HG. Do as other have suggested,try are eliminate one cause at a time,if the results are not whats expected move on to the next procedure. This way you may be able to separate or find they are related.