MR HYDROSEED

My truck has been doing this for awhile now, but its getting much worse. When I leave my driveway the tranny want to upshift up all the gears it seems. The TC must be locking up also because unless I hit the OD button it will stall out. Then I still may need to make a save by shifting it into 2nd. Sometimes it will upshift at a stop light while sitting there, stalling it out. My TPS is covered with toxic sludge, but is that the problem? After driving for 15 minutes it seems to take care of itself. Temp sensor? Speed sensor?
I was going to swap to a potentiometer, but doesn't that just effect the OD shift point? Oh, yeah what about dirty tranny filter and fluid?

custom66coronet

I replaced my TPS with a 5K potentiometer. because mine was quite dirty and after I cleaned it things got worse. no lockup before and switching between 3rd and OD with no lockup after. put a 1.2k resistor in place of the temp sensor as well. still playing with the potentiometer. but it locks up in OD about 45-50 now.

joshua smith

mine did this a couple years ago and it was the throttle position sensor

MR HYDROSEED

Keep in mind that I do have OD, most of the problems are from 0-55 mph. When I bought the truck I had OD problems but after rebuilding the valve body with a Goerend one it has worked awesome until now. I do feel that my tranny may shift a little sooner than I'd like. So a potentiometer sounds great for me, I wonder if theres a way to adjust the 1-2, 2-3 shift points?? Last spring I drove thru 4ft of sea foam, that rusted up everything it touched and made my truck smell like dead fish for months.