phil martin

I have a 2005 4.8l chevy tahoe. I have 4 gears just to put that out there so no one misunderstands this post.

I recently had to get a new torque converter and trans rebuild because in 4th gear it would violently shake uphill around 50. It no longer has that issue. Before and after the rebuild when my truck went in 4th gear the rpms would drop to 1100 to 1500 rpms. It was very sluggish and bogging out. Very hard to get up to speed. I recently bought a pcm from wait4me and told him I needed more line pressure and to adjust the shift points even higher hoping this would fix the issue or at least band aid it. After I installed the pcm my vehicle would stall whenever I took corners or came to a stop. He told me to clean my throttle body. I cleaned the throttle body and the MAF. Runs much better and feels like there is more torque. Not sure if it's from the pcm or from cleaning the throttle body. Anyways it runs nearly perfect... until 4th gear. It drops from 2000rpm in 3rd to 1100-1500 rpms. 1100 if I'm babying it and 1500 if I'm accelerating quickly. But when I tried to speed up it doesn't really go anywhere and bogs out. I have to almost floor it and it will "buck" immediately to 2000rpm. But when I let off just the slightest it drops right back down to 1100-1500. This happens anywhere from 45 (if I'm babying it) or 55 if I'm accelerating quickly. It's almost as if when I almost floor it.. it down shifts to 3rd and when I let off a tiny bit it goes back to forth. It's driving me nuts does anyone have any idea what this could be?

Thanks for reading my story...

phil martin

Also I can feel my down shifts when I come to a stop. Is this from the added line pressure or is this a bad thing?