'95 Escort Wagon - Weird Auto Tranny Problem

After sitting all summer, our '95 Escort (135,000kms) has developed a strange shift problem. It shifts properly from a cold start - drove it about 50 kms. this morning at high speed, just fine - until the key is turned off. When restarted, it will not shift first to second normally - revs go up, no speed increase, just like a slippling manual clutch. The shift can be forced by building the revs to near the redline - you'll feel the shift happen, and it's then OK until the key is turned off again. Every time the key is turned off when the wagon is well warmed up, this happens - shorter drives, it behaves perfectly - this is, you can turn the key off, restart, and it works fine.
I've had the fluid and filter changed, added a bottle of Lucas, and had my mechanic (he's good, but puzzled) go over it - he feels it's an electrical problem, rather than worn or defective internal components.
If anyone has any suggestions, they'd be GREATLY appreciated - facing $600-700 tranny transplant, and I'd HATE to find out it was an electrical bug all along.

Modern transmission are programmed to behave differently at different temperatures.

I drove a car with a stuck thermo stat once, that wouldn't shift into 5th, because that car never got warm eough.

Do some research, and find out exactly what your tranny will do in every situation. Check things like your engine tempurature sensor, and the wiring.

I don't really know anything about the trannys in these cars.. so I can't suggest anything really detailed. But the basics are always the same.

When this happens, you have to rev the car up real high, and then it dumps into second gear real hard right?

I had a car that did this once too. It's because the clutches wear out, and the worn clutch material clogs the tranny fluid chambers. So it has a hard time shifting.

God I hate transmissions in our cars..
My old escort did that, but I was lucky enough to change the fluid and the filter and got it to work for a few more months before I started to lose gears all together.

Thanks to a good tranny guy, we found the problem - a pressure regulator valve, accessible thru the tranny side - all sorted without having to remove the tramsmission. Running fine now.:grinyes: