Help .. BFR shifting problem

[straycat990]

Hey Guys, I have a problem with a 87 GN I just picked up. The Trans had been replaced with a General Motors replacement unit in 1997 but only has about 10,000 miles on it. The Tranny shift nicely except in WOT conditions. At WOT the tranny will not shift out of first gear. It hangs there in first gear until the gas pedal is lifted ..usually the TPS voltage has to drop to 3.90 volts before the tranny will **** to second gear. I thought maybe the dentent cable was not adjusted properly. I adjusted it and the problem persisted. I finally decided to actually miss adjust the dentent cable so that it was not being pulled to it full amount at WOT. This cured the shifting problem and the Tranny performed flawlessly on a WOT 1/4 mile pass but the tranny shifts were soft and slipped when engaging a gear while driving normally.

Any ideas whats wrong with this tranny and what needs to be done to correct it?

thanks,
David

 

[chris718]

the valve body needs to recalibrated or swapped out for another.contact www.ckperformance.com 718 784 4256 .this is too much to post .give us a call i need more info.