Golen 4.6 random misfires
Posted: April 7th, 2021, 9:19 pm
Hi All, I'm a noob to strokers and have pretty basic mechanic skills. I could really use some expert input on a persistent random misfire issue on my 2001 WJ.
I recently purchased a complete dyno'd Golen Engine 4.6 stroker with 62mm TB and headers and had it installed by my trusted mechanic. Since the installation the engine has been throwing random misfire codes P0300, P0301, P0303 when RPMs >2000, light or heavy throttle. My mechanic has done a lot of diagnostic work that I don’t have the technical knowledge to describe, but long story short the aftermarket sensors we transferred from the old engine all seemed to be operating fine. Fuel pressure is "good" and my mechanic seems certain this is a controls issue.
Based on recommendations from Golen and other Golen engine owners who had misfire issues, we’ve now replaced all of the following with new Mopar parts: cam position sensor, MAP sensor, TPS, ignition coil, all O2 sensors, O2 wiring harness, and oil pressure sender. We’ve reset the ECU, tested the new (Bosch?) fuel injectors and disconnected the PCV vent/plugged the intake manifold to see if the new valve cover was causing the issue. None of these measures have solved the problem.
We are now ordering a new (used) programmed ECU, and a used wiring harness to replace the oil-soaked harness that might be causing grounding issues. It’s my sincere hope that one of these will solve the problem as there isn’t much more we can do.
Your expert advice, dumbed down for a layperson, is welcome. Thanks in advance.
I recently purchased a complete dyno'd Golen Engine 4.6 stroker with 62mm TB and headers and had it installed by my trusted mechanic. Since the installation the engine has been throwing random misfire codes P0300, P0301, P0303 when RPMs >2000, light or heavy throttle. My mechanic has done a lot of diagnostic work that I don’t have the technical knowledge to describe, but long story short the aftermarket sensors we transferred from the old engine all seemed to be operating fine. Fuel pressure is "good" and my mechanic seems certain this is a controls issue.
Based on recommendations from Golen and other Golen engine owners who had misfire issues, we’ve now replaced all of the following with new Mopar parts: cam position sensor, MAP sensor, TPS, ignition coil, all O2 sensors, O2 wiring harness, and oil pressure sender. We’ve reset the ECU, tested the new (Bosch?) fuel injectors and disconnected the PCV vent/plugged the intake manifold to see if the new valve cover was causing the issue. None of these measures have solved the problem.
We are now ordering a new (used) programmed ECU, and a used wiring harness to replace the oil-soaked harness that might be causing grounding issues. It’s my sincere hope that one of these will solve the problem as there isn’t much more we can do.
Your expert advice, dumbed down for a layperson, is welcome. Thanks in advance.