Shift from 1 > 2 Loss of Power then Over-rev into Redline

[1FZj80]

I know little about auto tranny's.
After shift from 1 to 2, it feels like there is a loss in power.
Then as I step on the skinny pedal, something happens and the engine hits redline.
I'm guessing the tranny is slipping???
But, it is also is intermittent and does not happen all the time.
I am assuming this is a tranny issue?
Any ideas, suggestions...?

 

[Phildoh]

I agree, trans issue. The little bit I know about transmissions would be to hit the dealer for a diagnostic. I'm competent in function and design, but no tools to test anything, nor have I done it on an 80 trans. Curious to see what you find out, maybe a bad solenoid? Hopefully!

 

[LINUS]

What's it act like if parked or in neutral with e-brake on?

I had a throttle position sensor develop an odd "hop zone" instead of linear ohm load, it was a head scratcher 'till I got to it, my symptom was a weird "fighting itself" sensation, would rev slight but not deliver power for revs represented.

It only threw a code once - one of the generic ones, not a Toy specific one.

 

[1FZj80]

Parked or neutral seem fine.
Off the line in 1st seems ok too.
It starts with the shift from 1 to 2. Then it just seems like there is a loss in power, but no initial over-rev.
It snaps to redline when I keep depressing the throttle which is the natural driving response to the low power.
I'm hoping it is a solenoid or something other than a rebuild.
I think I will take to local shop, SD Trux with finger crossed...

 

[PBARDIS]

This is happening to me. Only in 4L. I've been reading this. How did yours turn out?
1993 FZJ80 Transmission slips in forward gears

 

[1FZj80]

I'm getting the tranny rebuilt now.
Something broke and bits of metal went through out the whole thing.
Also, I was having a drainback issue where fluid level cold was higher than hot. This should not cause a problem once fluid gets pumped back into the system, but I think there were other issues as well issues.
Should get it back next week.