A couple years back I rebuilt my TH400 myself and reinstalled it in the car. I had tweaked it to handle more power. I also installed a JW torque converter. Car drove great as far as the trans goes. Today I just noticed something weird. When I floor it, it downshifts fine. The engine revs up like it's supposed to. Then I get to the point where the trans should shift. It starts the shift and then the engine seems like it starts to bog down. I lift my foot up and the engine recovers/doesn't die. This only happens during WOT acceleration. During normal driving, the trans shifts like it is supposed to. No issues. Fluid is full, maybe slightly over. Any thoughts as to what may be going on?
Sounds like a fuel delivery issue, Check your fuel filter, or possibly the pump. The modern additives in today's gasoline are tough on the old rubber in the pumps.
Not saying you are wrong, but the issue definately has to do with the trans trying to shift while I got it floored. Though my initial feeling was it was falling on its face. So maybe. I will change the filter and check out the fuel pump.
You wouldn't believe how many transmission problems that come into the shop are actually fuel or ignition problems.
No, my plate of things to do is overflowing. So this issue will wait, but it's on my list. I will advise what I find when I get to it.
