Turbo 400 experts please step in....

[joespanova]

Originally Posted by Mark Ugrich

Check the vacuum at the intake as well. It’s been a while , but from my training during GM tech school, govenor pressure overcomes modulator pressure to make the shift. Someone correct me if I’m wrong, but I don’t think disconnecting the downshift solenoid will have any effect on shift timing.

Sorry for the confusion. The reference to the solenoid was about whether I can leave it disconnected and if that has any consequence . No connection to upshift timing.