Engine/Transmission (1994 - 1998) 96 auto shift problem??

[chopperman]

Greetings, my son has a 96 auto ctd the trans was rebuilt 15000 ago. He pulls nothing just daily driving to diesel mech school. Anyway he is describing a problem of shifting in and out of overdrive. When the transmission is in overdrive he says it seems to downshift then up shift. He said he hasn't noticed a large swing in rpms . I'm thinking torque converter but not sure . As always any and all posts are appreciated. Thanks, Brian

 

[GaryOwen]

Sounds like the Throttle Position Sensor (TPS) is starting to go. Try working the pedal up and down rapidly with the engine off. This will sometimes help for a short time if it is the TPS. The last time I had to replace mine, I got it from NAPA. Some have had some luck cleaning the TPS with contact cleaner (requires drilling a small hole to get good access to inside). Search for TPS and you will find lots of reading.

 

[BigPapa]

I'd second Gary's opinion. Also check the brake pedal switch. Before I converted mine to a 5-speed I replaced the TPS 3 times and the brake switch twice. There are all kind of TPS fixes out there. I never got any of them to work for me. The latest one, where you install a potentiometer in line, looks like it may be the way to go. It came out after my conversion or I'd have tried it.



Scott

 

[BigPapa]

I'd second Gary's opinion. Also check the brake pedal switch. Before I converted mine to a 5-speed I replaced the TPS 3 times and the brake switch twice. There are all kind of TPS fixes out there. I never got any of them to work for me. The latest one, where you install a potentiometer in line, looks like it may be the way to go. It came out after my conversion or I'd have tried it.



Scott