Originally Posted by RamTech
What was the throttle position when the code set? Have you checked the plug condition? Oil fouled plugs would cause a misfire and being those two cylinders are toward the rear making them prone to oil fouling from a leaking plenum pan gasket. What about the rest of the secondary ignition system?
Throttle position: I don't have real time data (yet) but I think it was around 35-40%.
I just got done pulling the plugs, injectors, injector rail, and scoping the cylinders and injection manifold. The plugs are clean, no fouling/funny smell/temperature damage. I have ran electrical checks on the ignition system running and off. so far nothing is wrong.
The injectors looked pretty nasty, but they all passed resistance and operational checks. when the injectors open, I get free flow from each of them (I don't have a test stand to see if they have good spray patterns and how well they are flowing at operating pressure though). I took the cylinder 5 injector and put in cylinder 1. I figure if there is a gremlin in there it should show up on cylinder 1 now.
Any ideas on the secondary fuel system? is that the fuel return system?