4l60e not shifting into 2nd unless you let off gas

[Nessiepark56]

i've got a 1993 k1500, 15 years ago i replaced 3-4 clutch pack and accumulator which should have been a recall. No problems since. Last week i replaced the 1-2 accumulator piston with a sonnax pinless, and installed super hold servo 1-2 piston and separator. Still not shifting into second unless i let off gas. I did a pressure test today with the following results: 80psi in park and drive. 110 psi in reverse. 150psi in mannual 1-2, and 150psi at wot and at wot sounds like it is slipping. I realize with almost 289k on the almost 30 year old truck, I should be happy with the reliability it has given me. Just wondering if someone might have a magic wand [IDEA] of what bandaid I could put on it to keep it going? I know it needs to be rebuilt. I'm 70, and hope I got it in me to pull one more tranny. Thanks for any reply. Also tps and vss are good according to my test.

 

[618 Syndicate]

Edit, just realized you already checked the TPS.
What was the voltage key on engine off?

 

[Schurkey]

Connect scan tool, look at the data stream for the trans, and for the engine. Might be worth looking at the shift compensation--if the computer is working hard to sharpen the shifts, the trans may not be long for the world.

How old is the trans filter? I fixed a Trailblazer that wouldn't go into reverse when cold, by flushing the fluid and replacing the filter.