Hard Shift 1-2 gear

[BOTTLEDZ28]

My 98 does the same thing but I think it may be in the tune. I am running a 0411 ECM. Another issue I do have is that the converter unlocks while cruising down the highway when its raining out. Then, it will lock back up again like nothing happened. I dont think its the brake switch but its weird that it only does it when it raining out. Not sure of both problems are related.

 

[Eveready]

My 98 does the same thing but I think it may be in the tune. I am running a 0411 ECM. Another issue I do have is that the converter unlocks while cruising down the highway when its raining out. Then, it will lock back up again like nothing happened. I dont think its the brake switch but its weird that it only does it when it raining out. Not sure of both problems are related.

One thing I did to my old van that had brake light switch issues (the pedal was not adjusted properly and it kept blinking) was put a piece of elastic (or a large rubber band) on it to exert positive pressure on it to help the spring keep the pedal at the top. This kept the blinking from happening and all of a sudden it would remain in lock. It is a very cheap way to see if the problem changes, just don't prevent yourself from using the brakes.

 

[BOTTLEDZ28]

Just to update my issue in this thread. I found the cause of the late and harsh 1-2 upshift. It was a broken inner spring inside the 1-2 accumulator housing Ordered a new spring and now Im good. Well, except for the feeling of something slipping in the trans when I step on the gas to pass to someone and it downshifts to 3rd and the tach jumps to 4K and the truck doesnt ready go anywhere.

 

[ima93chevyguy]

Well I finally found the problem behind my harsh shifts.

It was the ECM

I swapped in another computer from a 94 model and it completely solved my problems. Every issue I had went away and it's normal now.

So I'm going to get a new computer and swap in my PROM, if that doesn't fix the problem then it must be in my PROM.