Attention: TDR Forum Junkies 
Searched for something similar to this with no results.
The problem is intermittent.
The truck will drive just fine one day, park it in the garage, start it the next morning and it doesn't want to go into overdrive. I can trick it into making the up shift by letting off the throttle and slowly easing back into it.
Additionally, when this is happening, it won't disengage lock up when the throttle is released. Doesn't matter if I have the OD off and it’s in 3rd gear lock up, or if it has been tricked into OD and in OD lock up. Let off the throttle, stays in lock up. Press on the brake, lock up disengages. Let off the brake (still no throttle) lock up reengages. Lock up WILL disengage when below the appropriate speeds, 45ish in overdrive for example. There's no hunting for OD or Lock up or anything like that.
So, it's as if the truck randomly thinks that I have my foot on the gas when I don't. My first thought was the TPS. I tested it, voltage was high, couldn't get it any lower than 1.5v, replaced it. The new one tests at 1.1v, within spec. Checked the throttle linkage measurement too; it was dead on.
My idle is set a bit high (850-900) and I was thinking that maybe that could be a cause, but it has been set that way for a long time and was never a problem before.
Not sure what to make of this and everyone else seems to have the opposite problem....
Anyone ever seen this?
The problem is intermittent.
The truck will drive just fine one day, park it in the garage, start it the next morning and it doesn't want to go into overdrive. I can trick it into making the up shift by letting off the throttle and slowly easing back into it.
Additionally, when this is happening, it won't disengage lock up when the throttle is released. Doesn't matter if I have the OD off and it’s in 3rd gear lock up, or if it has been tricked into OD and in OD lock up. Let off the throttle, stays in lock up. Press on the brake, lock up disengages. Let off the brake (still no throttle) lock up reengages. Lock up WILL disengage when below the appropriate speeds, 45ish in overdrive for example. There's no hunting for OD or Lock up or anything like that.
So, it's as if the truck randomly thinks that I have my foot on the gas when I don't. My first thought was the TPS. I tested it, voltage was high, couldn't get it any lower than 1.5v, replaced it. The new one tests at 1.1v, within spec. Checked the throttle linkage measurement too; it was dead on.
My idle is set a bit high (850-900) and I was thinking that maybe that could be a cause, but it has been set that way for a long time and was never a problem before.
Not sure what to make of this and everyone else seems to have the opposite problem....
Anyone ever seen this?
