Thank you for the follow up madmike1735.
I had replaced the original coil pack with an aftermarket couple of years ago as a "routine maintenance". The original coil was working fine so I had kept it as spare. When misfire started, I first swaped with the original coil that I had kept and then got another brand new one. Both swaps didn't fix the problem.
Regarding spark check, I used an inline spark tester that flashes and things looked ok. I then decided to do an alternate check by pulling the wires and holding them close to the spark plug tip. My plugs sit between exhaust manifold and what I noticed was that bright white sparks arced to the manifold in a circulation on each fire on cylinder 2 4 and 5. On the other three cylinders I saw small bright white arc going between wire and spark plug tip. When I turned the a/c on (this is when misfire is most obvious) and reved the engine, sparks on 1 and 6 disappeared. I didn't check 3, but I think its safe to say that it lost the spark. As well.
I have checked and rechecked for cross wiring. My wires and coil have numbers on them so its difficult to make mistake.
I was considering replacing crankshaft position sensor but something tells me that's not the problem. Mostly when crank sensor fails, there is no spark on all cylinders.
The van shudders badly over 40; you can't drive the thing so I am baffled why its not setting at least some code.
Wednesday, October 2nd, 2013 AT 1:11 PM