Here are the symptoms of my automatic 1998 Z-28. It works perfect when driven propperly. If I floor it from a dead stop or rolling (up to about 25-30) it shifts second great but then when its time for third, it doesn't shift and I think the rev limiter kicks in so it doesn't blow up. If I give it 80% throttle (which still launches pretty good) it works perfect and shifts all the gears perfectly.

Second symptom. If I am doing 60 mph or so, and basically floor it, it pulls good up into 75 or 80. Then it seems to be slipping or not shifting into overdrive. Its the same thing with the 80% throttle deal. It works great it its no floored.

So for an answer, please don't tell me that my problem is I have it floored. I think it should work perfect floored if my tranny were working perfectly. By the way, floored is not often.

Here is what I think it could be. Low tranny fluid. So you are all wondering, why don't I check the levels. I have and it reads good but I don't think I have the original or correct dipstick (I bought the car used a month ago)

Any suggestions? and one other question. How much does heat affect performance of the motor. Today in CT, we reached 90 degrees and I swear it seems like the car is driving much more sluggish in the heat. Temp is good and coolant is at the correct level. Am I imagining this?

 

Firstly cars run worse in the heat cause the air is warmer and less dense and it will feel more sluggish, nothing you can do about that

A couple of things with the tranny do you mean it wont shift to third with the lever already in 'D' when floored? The only difference when floored is that it works off RPM not speedo as it does under like 80% throttle. It could be a number of things, have you looked at the 4L60E common problems??

 

Yes, I mean it won't shift into third with it in "D" (drive with overdrive or drive without overdrive). No, I have not looked at the common problems but I will.

 

Check your trans fluid first off. Look and make sure its at the correct level and that its not burnt.