Tranny weirdness II

So I've been having this ongoing tranmission problem on my 96 4.0 sport auto 231.

Every now and then when I go to take off from a dead stop the tranny slips until it get to 10 mph then it is fine. It feels like it is taking off in second gear. The other day it started acting up so I shifted to d3 and it still slipped, but then I shifted into d1-2 and it took off fine from a dead stop, reverse works perfect too. I'll park it and a few minutes later it is working great again.

I'm thinking at this point it has to be something like the NSS (which was acting up last year so I replaced it with a used one, maybe needs adjustment) or some other electrical problem.

Any ideas?

Personally it sounds like a pump going bad. When in reverse, the pump puts out the most pressure, so reverse should work fine. When the seals in the pump start getting bad, they tend to leak at low rpms, especially when cold.

Actual "slipping" is more apt to be internal to the transmission, and not electrical. This doesn't sound like an NSS issue or even a TPS issue to me.

I think I'd get the actual line pressure tested at a shop. Would be a good data point.

How many miles on this transmission? Fluid at the correct level, red in color, and not smelling burnt?

I would test the shift solonoids. I would say you are in the early stages of them going bad especially the 1st gear. There is a procedure for testing them here on using a VOA (Ohm) meter. Because you can manually shift it and it work fine is an indication that there is nothing mechanically wrong with the AW4.

I thinking the same thing. The tranny has about 160 miles on it , the fluid was changed about 6 months ago. The problem happens only when it's hot. This weekend it was acting up toward the end of a drive to upstate ny, about 60 miles away. But on the way back home it worked perfect.

I would think a bad pump would still slip in d1-2, and would be worst when the jeep is cold.