1995 camaro Z-28, auto-runs perfect, 90K miles.
Engine goes past rev limiter on 1-2 shift and 2-3 shift. I just had my tranny rebuilt by an experienced shop. no codes, Chevrolet can't find nothing.
Is it the ECM or ???

 

its an lt1, who cares

 

The problem is that it totaly misses the shift and you have to back off the throttle for the shift. Anything under 4500 is ok, but over that it hits the rev limiter and doesn't shift.
Actually it goes right over the rev limiter. Something makes this car shift. ECM, valve body and ....?

 

Locate a 4th gen site. This is a THIRD gen site.

Off hand I would think it's got to do with skip shift.

 

Try the transmission board. Other than that the transmission is run by the ECM and shift solenoids in the transmission. Also check you VSS connection and transmission harness connector.

 

If you're running more than a ~3000 stall converter it's a real common problem on electronically controlled automatics in 4th gens. It'll often bounce off the rev limiter and not shift, or only shift after it's bounced off it a couple times. If that's not it, I'd have to suspect internal transmission problems.

You need a better tranny guy than me to help you any further.

 

camaroz28.com
lots of info there