My 1994 F150 5.0/E40D with 215,000 miles was shifting poorly; sometimes upshifting too quickly, sometimes refusing to downshift, sometimes downshifting into 2nd on the highway.

After consulting the wealth of information in this forum I purchased the $31.99 Equus Innova 3145 Digital Code Reader from my local O'Reilly Auto and confirmed what I suspected - the computer was receiving faulty readings from the Throttle Position Sensor (code 121, in my case).

I purchased a $22.89 Standard TH44T TPS from Rockauto.com and got to work. This is a non-adjustable type.

It took me about 10-15 minutes to have everything apart and ready to go back together, mostly spent determining which tools I needed and walking to the shop to get them.

I ensured that the connector pins were not corroded and that I properly installed the sensor by inserting about 1/4 counterclockwise and then rotating clockwise to the proper position for the screws. I plugged in the (2) sensors on the throttle body and re-ran the Key-On-Engine-Off (KOEO) test again with the Equus and got a clean bill of health. I then cleared the computer memory and buttoned everything back up in about 5 minutes.

It made a world of difference in the transmission shifting. It now shifts as smooth as you like, it upshifts, it downshifts, it cleans bathroom soap scum.

Below is a picture of the old TPS. I'm going to go out on a limb and say I think I can guess what the issue was.

 

Excellent find, thanks for the feedback!

 

Good job on the fix!!!!
Thanks for the report!!

I wish more people would take time to get codes and do the needed repairs before they call the E4OD a piece of crap.. I would bet 75-80% of the E4OD problems have nothing at all to do with the trans..

You just proved that is possible with yours..

Rant off.......