TPS Question

[BillGotthelf]

Hey all you 1st gen guys I have a friend who is experiencing the famous OD in and out from 45-60. On the later trucks all things point to the TPS. His is a 93 auto-is it the same on his truck?

 

[BushWakr - RIP]

Yup, the primary function of the TPS is to govern the 3-4, 4-3 shift.

If the TPS is dirty, worn or pooched it will mess up that shift.



First thing to do is check the voltage on the TPS with the ignition key 'ON' (don't start the truck). With the key on, you need to use the center wire for your "+" probe on the volt meter and the negative can be connected to the battery "-" terminal.

Make a note of voltage. Normally it will range between . 6vdc and 1. 2vdc.

Second, with the voltmeter connected, cycle the throttle slowly and smoothly to WOT. Watch the needle... is should move upward in a smooth non-twitchy movement.

The upper end voltage reading when the throttle is at WOT should range between 2. 25 and 2. 75 volts OVER the at rest voltage.

Raising the initial voltage will delay the 3-4 shift, and lower it will make the 3-4 happen sooner.



He should also make sure that ALL his connections under the hood and on the trans. are clean and free of dirt or contaminants. The TPS is not the only sensor/controller that is tied in to the PCM, all of which has an effect on transmission, engine, and pump functions.



Hope that helps... .



Pastor Bob.

 

[1stgen4evr]

OD in and out

If you get your friends truck going correctly by setting the TPS, consider yourself lucky, lucky, lucky. This is the one part of the first gen trucks that makes me want to puke. I am changing my late 92 ctd auto to manual and the connected stuff is going in the trash.



Joe down at Sun Coast told me he can make it work like new. I have no reason to doubt him but since the 92 never worked right from new, 'that ain't good enough for me'. That and 250k miles along with the desire to try a comparison of the Getrag and the NV4500 have motivated the conversion. I have 395k on a 93 ctd with the Getrag and another 'Sunday driver' 93 ctd that is automatic with 90k on it. When it needs service I will be taking it to Sun Coast. I am considering an 89 ctd that has the 727 and 3:07 rear. No computer, no TPS. But it doesn't have enough gear ratios to get the most from the Cummins.



If someone would put together a really bullet proof industrial PLC to control the piddly stuff the CTDs need with industrial strength wireing and connectors, I think the OD, alternator, airconditoner and cold operation issues would work right. The wireing and connectors that Dodge used just don't get it done.



My two cents worth.



Best of luck with whatever comes next.

1stgen4evr

James

 

[shendren]

i have put together a tps rewire kit over on the classifieds. works like a charm. no more new tps's... ... .