Getting a code 300 random misfire, was showing misfires at random times on 3,4 and 6. One coil was cracked and replaced. Plugs on 3 and 4 removed, usual wear ( had been replaced about 31K Km ago). Compression on both 3 and 4 90PSI, these 2 cylinders have historically been lower than the rest.
Ignition module swapped out for a used one
Some wiring issues with grounds for PCM and ICM corrected.
Plug wire on #4 changed out.
Fuel pressure at 41 PSI if vacuum line to regulator removed; otherwise runs about 37 PSi at idle. Clamping off fuel return line can generate 60 PSI, so regulator suspect.
Van starts great, idles ok, but under even just a slight load #4 cuts out, showing misfire on the scanner I have. After all this work, it is now only #4 that is acting up. This was sudden onset, about 2 weeks after catalytic converter was replaced
Any suggestion? Better half pushing to kick tires on a replacement