tps question?

[Joe G.]

There are a couple of things you can do to overcome the TPS problems. One is to install a pot in the ground line so you an adjust the voltage properly. The adjustment procedure in the service manual is worthless.

The other thing you can do is to replace the TPS with a pot in the cab. Then you can dial in your shift point speed. If you do that, there is no funny business with shifting in and out of OD and/or lockup just because it feels like it today. However, if you use a pot to set OD lockup speed, kick down does not work.

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KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4, 3.54, EGT, boost, fuel pressure, trans temp guages, PacBrake, TST #5, DTT VB, DTT triple disk TC, DTT billet flex plate, Cummins chrome kit.

[get R done]

Originally Posted by illflem

If you unplug the TPS there should be no voltage on the output wire back to the PCM.
If there is around 5 v you have a short somewhere or a bad PCM.
If there is zero volts on the output with the TPS unplugged but 5 volts with it plugged in the TPS is bad.

Which wire is the output wire just to make sure i was checking the right one,because i think i probed the black and orange wire with it unpluged ignition on and got 5volts.and with it plugges in i still get 5.38 volts with ignition on and throttle at idle position.Correct me if iam wrong but i have the washer kit mod done to the govenor springs in the pump would this be causing my problem or not,just a thought.

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1996 3500 ext.cab 2wd,modified trans.&torque converter,HTB2 62/14 turbo,#10 fuel plate,4"exhaust,autometer pyro&boost gauges.

[Joe G.]

No. The TPS only measures throttle position. The TPS usually gets dirty so the signal is ratty. The stock adjustment procedure does not quite get the signal voltage at idle up to the .8 volt spec on a lot of trucks. For some reason the '96 has more problems then other years. If you adjust it so that the voltage is where it should be using the service manual procedure then you either mess up the idle or it won't go to WOT. Some of drilled out the TPS mounting holes to allow more twist, but that does not always work and sometimes destroys the TPS. You can clean it by taking it apart with a Dremel tool, but that cleaning does not last very long before you have the same problems. If you disconnect the TPS and install a pot all that funny business goes away. The guys that have done that really like the way it works. An alternative to allow adjusting the TPS easily so it is within spec is to install a pot in the ground wire. By doing that you can adjust the throttle rod so that the throttle works right and you can still adjust the TPS. Even then you have to clean it once in a while.

__________________
KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4, 3.54, EGT, boost, fuel pressure, trans temp guages, PacBrake, TST #5, DTT VB, DTT triple disk TC, DTT billet flex plate, Cummins chrome kit.

[illflem]

Orange is signal wire, purple 5v supply, black ground.

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Bill
'95 2500 4wd auto
'95 3500 5 speed heavy hauler
Not stock

[get R done]

Originally Posted by Joe G.

No. The TPS only measures throttle position. The TPS usually gets dirty so the signal is ratty. The stock adjustment procedure does not quite get the signal voltage at idle up to the .8 volt spec on a lot of trucks. For some reason the '96 has more problems then other years. If you adjust it so that the voltage is where it should be using the service manual procedure then you either mess up the idle or it won't go to WOT. Some of drilled out the TPS mounting holes to allow more twist, but that does not always work and sometimes destroys the TPS. You can clean it by taking it apart with a Dremel tool, but that cleaning does not last very long before you have the same problems. If you disconnect the TPS and install a pot all that funny business goes away. The guys that have done that really like the way it works. An alternative to allow adjusting the TPS easily so it is within spec is to install a pot in the ground wire. By doing that you can adjust the throttle rod so that the throttle works right and you can still adjust the TPS. Even then you have to clean it once in a while.

Thanks for the info but what is a pot and how do i install it on my truck because i have tried what you said drilling the mounting holes out and that helps a little but still shifts bad sometimes and i drilled two holes in the case the size of the spray wand on a can of electrical contact cleaner and sprayed it in one hole and and there was a little bit of black dirt came out the other one then i just sealed the little holes up with some silicone.

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1996 3500 ext.cab 2wd,modified trans.&torque converter,HTB2 62/14 turbo,#10 fuel plate,4"exhaust,autometer pyro&boost gauges.

[Joe G.]

Read this thread: TPS myth buster - TDR Roundtable

Note that ridesamule has a 47RE transmission and Howard Durand has a 47RH so this applies to both transmission types.

__________________
KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4, 3.54, EGT, boost, fuel pressure, trans temp guages, PacBrake, TST #5, DTT VB, DTT triple disk TC, DTT billet flex plate, Cummins chrome kit.

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Last edited by Joe G. : 09-13-2007 at 10:21 AM. Reason: Added explanation line