TCC lockup causes more load on the engine, resulting in higher misfires. This is common with an engine that has issues.
Verify that fuel pressure is INDEED within spec. Countless times I have seen people here say they checked FP and it was NOT within spec.
Also verify FP regulator is ok.

Big update. Turns out it was multiple problems. There was a stuck valve, part of the valve body gasket broke off and was lodged in there, and the torque converter was bad. So, new valve body, and another new torque converter.

I still have his coils, plugs, and wires on there from the troubleshooting. He’* not sure he’* replacing the motor in his Ultra, so I may just buy the parts from him. They’re ZZP parts and the car is running better than it has since I’ve had it.

Cool!

Sounds like that transaxle has been apart before.

Thanks for letting us know how it turned out!

Ugh. This soap opera continues. Now, when cold, shifting back to first from second at mid-high revs as if to pass, it’* dropping RPMs and then slamming into 1st. Back it goes. Otherwise, it’* running great. Once wam, it doesn’t do that.

Sounds like maybe a bad TPS or MAF.

It'* driving along happy, you open the throttle plate a bunch, it doesn't measure that air coming in and temporarily leans out while the transmission is oblivious and downshifts, then the engine figures itself out and BLAMO you're on your way.

Could be a big vacuum leak as well, come to think of it.

It will be back to my mechanic soon. If I get time I’ll look it over, but I know what it’* like messing with it if I’m going to have him work on it. I’d be frustrated and skeptical in his shoes. That said, I texted him the new code: p0742 TCC circuit stuck on. Ugh.

Does it have lazy 1-2 and 2-3 shifts?

Things have been nuts for me and my mechanic. He’* a one-man show, so here we are. Just got it back again today. He found a short at the TPS plug. Basically, he crimped the wire when he did the motor swap and found it now. We’ll put some miles on it and see if I want to you his parts.

So bad TPS reading then?

Glad he found a smoking gun! Hopefully that'* what fixes it.

Looks like it. Will know more as we put miles on it. Not sure when we’ll drive it, though. Family Christmas gatherings are at our house and across the street at my mom’*. So, our cars aren’t going anywhere.