Hey guys, as you can see I am new here. I'm having trubble with my Z, I can shift threw all my gears including reverse while the key is in the off or aux. position. When I turn the key to "on" I only get 1st and 4th (running or not)... Scratching my head here.
If anyone has any feedback that would be great! Thanks.

 

Sounds like there's a short in the "skip shift" solenoid or it's wiring. That's the device that prevents you from shifting directly from 1st to 2nd at low RPM/low throttle acceleration. It should only activate when the PCM commands it, based on the RPM and throttle position percent. Sounds like yours is shorted, and blocking the shift at all times.

Always helps if you include specific info about your car, like the year. Here's a diagram applicable to the 94-97 T56 used with the LT1 (look at the bottom of the page):

http://shbox.com/1/1995_pcm2.jpg

If you have a different year, it may have different wiring.

 

The two plugs for the reverse lockout solenoid and CAGS solenoids are switched. Switch them.

Reverse is on by default unless key is on and speed is low enough.
CAGS is only on above certain speeds and at lower throttle position sensor readings.

 

Good call......

 

Thank's you guys. Ya I bought the car just about as it sits, it's a 1994 Z28. The guy who had it before me swaped in another LT-1, my guess is a newer one. But your right the wires were switched between the reverse lockout and speed sensor. got all my gears now.