Can any one enlighten me as to why my 89 XT6 2X4 flares into high gear? It also has what I'm told is morning sickness, where it won't move for 3-4 seconds after setting for a couple of hours. I spent a thousand dollars on a rebuild and it still does the same thing it did before I threw all that money at it. The rebuilder is blaming the car. Could it be the computer? Is there any way to disable or go around the black box? I would not have a problem with flipping a switch to lock up the convertor and eliminating the magic in the box. I love the car except that every time it shifts into high, I just grind my teeth, cause it just can't be right what is happening here. Thanks in advance for any help or advise.mb

Assuming it's an automatic, Tim thinks it sounds like the modulator valve... it's cheap to change. Good luck!

Mary

Sounds like a crappy rebuild to me.

Generally speaking,auto trans "morning sickness" is due to leaking seals that improve with heat.

 

"Could it be the computer?"

Maybe the flare,but I doubt it.Definately not the morning sickness.Don`t think you can disable it.

 

Which part of the car is your rebuilder trying to blame?

Only relavent item I can think of is low engine vacuum and that wouldn`t give your symptoms.

Regardless a tranny man should be able to diagnose it.

 

I would take it somewhere else for a written diagnosis,pressure test etc.About 1 hour of shop time.