Fuel Pump Blues, take TWO.

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I have not run logs, but the fault is multiple random misfires.

I've checked for air leaks, low fuel pressure/flow, and dirty injectors, fuel filter etc.

And even put a secondary fuel pump into the system because I could not get the stock fuel pump out of the tank. (the captured nut in the tank/siphon cup just spins in place, so the fuel pump housing can't be removed without some serious cutting/surgery/cost.)

The in line fuel pump is a Walbro 255lph all metal unit, and is working great. I'm not actually sure the stock pump failed really, since it's not noisy, and clearly, with the Walbro on there, the two of them are supplying PLENTY of fuel.

I've pinched the fuel return line (Using needle nose vice grips with short sections of hose over the jaws, so they would not cut into the fuel return line, I could vary how open, or completely closed it was, while the engine was running, and while driving it) so a failing fuel pressure regulator is not the problem.

It runs totally closed off actually, and while it did not run as well, but ran still, so I'm pretty sure the fuel pressure regulator is working as designed, but I don't have a way to measure pressure, just flow, and I've not done that, as it would require me to remove the fuel line and I also don't have a measured container to use.

It has to be either a failed coil pack, or some sensor that's throwing out a multiple random misfire.

I have swapped the coils around too, just to see if it would show up as a single coil, or even pair of failed coils, and no luck. The CEL still flashes, and pulls the code of "Multiple Random Misfires."

I have not done a log yet, and I'm not sure I know how actually. LOL is it a feature of the RossTech program? I've only used it a few times, so I'm not an expert on the system yet, but I've worked on, and built engines for more than 25 years, and this problem has me stumped.