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Cylinder contribution test 95 PSD?
I have a 95 PSD in an F450 that has at least one bad injector in it. The Contribution test always passes, even after 10 consecutive runs, with a definite miss in the engine. When the first part of the test initiates, the test drops one cyl at a time (or so it seems to do that). some cylinders show a drastic change, while one or two show little change at all.
The problem injectors i am looking for, arent totally dead, but miss at idle and under 1800 RPM, especially when hot. I was wondering if anyone knew if the cylinder contribution test was run in any specific order? If it is then I can go after the next injector, or possibly Orings that are bad, by listening to the one that doesnt change as much as the others.
I would assume that in 95 the ECM was new enough that this test wasnt totally de bugged. The only other way that i can think of is puling the valve covers and pulling injector wires one at a time, which I think I did a few years back to find the bad units. This was a messy ordeal as I remember.