Had to swap out my engine/trans wiring harness. The one I got from the scrap yard was missing the trans connectors, so I cut the ones off my old harness and spliced them onto the new one. I have 1st and 2nd gear but no 3rd or 4th now. Is it a single solenoid that controls 3rd and 4th gear? There were a couple wires in the harness that were identical colors. I did a continuity test and traced the wire back to the PCM connector to identify these, but I suppose it's possible that I crossed two of them by mistake. Anyone have any ideas?

 

There are actually two shift solenoids that control the shifts in a 4l80e. Why did you replace the harness in the first place?

 

I had my old harness all hacked up for various reasons. Switching back to the blower and I would have had to put everything back to where it was before. Much easier to just swap the harness.

Anyway, I dunno what the problem was but it's gone now. Everything is working fine. Easiest fix ever The only thing that wasn't plugged in before that is now is the IAT sensor.

 

That's good to hear. I wonder if maybe you had cycled the key or something and the computer went into a limp mode. 2nd gear in an 80 is a limp condition. Did the truck shift on it's own or were you manually shifting it when it only had 1st and 2nd gears? So are you switching back to the maggie and removing the turbo? Why? Looks like in your Sig you put some good #'s down with that combo if I read it correctly. Vince


BTW how many miles on the FLT 80?

 

It shifted on it's own from 1-2.

Yep turbo is gone, wanted to try the TVS pretty bad, and I was worried about pushing the turbo too much further with the log manifold setup. I know parish didn't have any issues but I was nervous after toasting my other engine. Plus I really like the simplicity of a blower setup.

I think I'm at about 8000 miles or so on the trans. Holding up great

 

That's great news. I have seen a few budget builds go south in less than half the miles lately. I guess you get what you pay for! I look forward to the new #'s with the new combo. Good luck. Vince