I've got a 92 Z28 with an auto. trans. that has been driven only about 1000 miles per year over the past 10 years...got 91000 miles on it. Recently, I started having a problem. When I start it and head down the road, the trans. seems to not want to shift into 2nd....RPMs don't jump. After about a few minutes of driving, it shifts into 2nd....no problems after that until the next cold start when the same thing happens. Is this a sticking throttle valve?

 

90% of tranny problems can be solved by replacing the fluid and filter. Try doing this and see if the problem goes away, gets worse, or stays the same. Check the filter/fluid for metal particles as well.

 

I replaced the trans. fluid and filter about 7 years ago....driven about 7000 miles since. I had the fluid flushed a few months ago (no new filter).

 

Make sure you have no vacuum leaks. Check vacuum source and make sure your throttle cable is properly adjusted. I would begin looking at the governor and valve body. Check for any visible damage or any possible sticking. That would also be the perfect time to add a new filter on as well. You might want to test pressures before doing this.