Engine/Transmission (1994 - 1998) TPS ADJUSTMENT questions

[stumphumper]

While replacing my throttle cable I took off my tps, clean it up so it rotated better, and reassembled. Replacement of the ball heads required adjustment of the linkage. I measured the 5 inch start point and then started to adjust the rod out trying to get 1 volt out of the center contact. I have 4 volts going in and with the TPS unbolted It will rotate and put out up to 3 volts. When bolted back on it reads 0 volts and I have to move it about 3/4 inch before it reads 1volt and at full throttle only 2volts. Is the TPS bad??? very expensive item that show good when not mounted up. What do you think Help! ken

 

[Joe G.]

The linkage adjustment procedure to set the TPS really does not work. If you get the voltage correct, then idle is probably messed up. There are other ways to do it. Read this thread: https://www.turbodieselregister.com...mission-1994-1998/156901-tps-myth-buster.html

 

[Bob4x4]

While replacing my throttle cable I took off my tps, clean it up so it rotated better, and reassembled. Replacement of the ball heads required adjustment of the linkage. I measured the 5 inch start point and then started to adjust the rod out trying to get 1 volt out of the center contact. I have 4 volts going in and with the TPS unbolted It will rotate and put out up to 3 volts. When bolted back on it reads 0 volts and I have to move it about 3/4 inch before it reads 1volt and at full throttle only 2volts. Is the TPS bad??? very expensive item that show good when not mounted up. What do you think Help! ken

Replacement of the cable and ball studs was covered by a recall 970.

The tps should be rotated slightly as it goes in to it's mounting location. The tps is not at it's rest position when it is mounted up. The tps does not affect idle speed. If you can not get 1. 0v(+ or -. 2v) at idle and still acheive full throttle you will probably need to replace the sensor assuming your input voltages are correct. You should also check the bushings for wear in the bracket assy,if there is too much play the sensor can not work correctly



Bob

 

[stumphumper]

thankyou Joe, that is a lot of great info that I will have to print out and go over. Bob, I had it all apart and the plastic bushings are still good. Its just that the TPS has a full range of 0-4v when it is rotated off the mount so I have a hard time thinking that the TPS is bad.

 

[Joe G.]

The throttle linkage does not rotate the TPS for full travel so you are not going to get 4 volts with it in place. Adjusting the linkage in an attempt to get it to do that usually gets the linkage out of adjustment as far as the injection pump is concerned. That's why putting a pot in the ground wire for the adjustment works so well. You can set the linkage for operating the throttle lever on the IP like you want and adjust the pot to trim the TPS voltage range.