Here's the story, I recently picked up my 95 XJ off my brother. Water pump was bad and had a few odds and ends but for a 1000 bucks, ill take the running driving 4x4 XJ. My buddy and I swapped the waterpump, belt and the vacuum line leading to the fuel rail. She started up just fine and ran peach! That was till she didn't, as we drove a little the poor cherokee began to sound like a damn Detroit Diesel. I thought maybe i had left a pully loose or didn't put some piece of bodywork back on properly and it rattled around. After some driving and minor diag we decided its likely some kind of ignition knocking. It only happens at certain throttle inputs, when the engine is fully warmed up and it will often backfire at the same time that its knocking. The knocking is not RPM dependant (it usually happens at 2500rpm, but only if brought there from a quick throttle snap, a slow raise to rpm will not yield knocking). My real question with all of this is, how should I do an in-depth diag?
should I pull the plugs and check for issues there, smoke test my vacuum system (or blow a ciggy into the manifold lol), ohm and continuity test my PCM? whats yalls advice?
sorry if this thread is in the wrong place, Im new lol