Engine/Transmission (1994 - 1998) 95 auto shift prob

[Deerediesel]

Friend of mine bought a 95 auto with a fresh transmission in it and it doesnt want to go into O/D or lock up until u let out of the throttle quite a ways. Checked the TPS and all was good. Im not a auto guy so someone please enlighten me.

Thanks

Shane

 

[Howard Durand]

It is possible that the TPS voltage is a little too high. Adjusting that can be difficult but it can be done.

I am not familiar with the hydraulics of the transmission but there may be a pressure adjustment to compensate for this.

Do you have any idea who built the transmission? If not, call Bill Kondolay at DTT. He could tell you if it can be changed.

The DTT transmission I have does the same thing but I like it. The TC also stays locked when I lift off of the throttle. That improves usage of the exhaust brake.

There has been quite a bit of discussion on the forum about TPS voltage and adjustment. I could help you with that if you want. If so, send me a PM with your e-mail address.

I'll send you a diagram of the circuit with instructions on how to put it in and how to use it.



Howard

 

[Joe G.]

In addition to what Howard says, check to see if the TV cable is too tight.

 

[Deerediesel]

Thanks for your replies guys. Ill look at the TV cable first and go from there.



Howard,

When your talkin about the voltage being too high(within specs), do you mean the stock voltage is too high?



Thanks,

Shane

 

[Howard Durand]

Shane,

The TPS has three wires plugged into it. The Purple/White wire has a constant 5 volts, the Black/Light Blue wire is ground.

The voltage that the PCM uses for transmission control is on the center wire. It is the Orange/Dark Blue wire.

Voltage is measured between that wire and ground.

I believe it is normally supposed to measure between 0. 8 and 1. 0 volts when the TPS is at rest and increases as the throttle is advanced.

If the at rest voltage is increased to around 1. 3 volts the shift pattern may change and, on mine, the TC stays locked up when the accelerator is released.

The TPS is not satisfactorily adjustable but that can be overcome fairly easy.

 

[LDPetersen]

TPS problems

I have had tps problems in the past. The one on my 95' ctd now is bad. I had the last one the dealer replaced a few years ago, and I spray cleaned it. It works a little better than the one that has been on it for quite a while. I guess I will need a new one. Is there any adjustment to try first? Also is NAPA the best price on a new one? $178. 00 on line. Or does anyone have a better place to buy one. Hope someone can help. Thanks Larry.

 

[Howard Durand]

Larry,



A good way to test the TPS is to connect an analog voltmeter between the center wire of the TPS and ground. Use a low voltage scale. Turn on the ignition and watch the meter as you move the throttle. The needle on the voltmeter should follow the movement of the throttle up and down smoothly without any interruption. If it jumps around while moving the throttle, it is either dirty or defective.

The at rest voltage should read between 0. 8 and 1 volts and move up to around 3 volts at full throttle.

 

[LDPetersen]

Thanks , I'll give that a try this weekend. Any ideas on a new one, best price?

 

[rrausch]

You'll have to do some homework in order to decide which is the best aftermarket Trans. I went with ATS in Denver for mine, on my 1995, 2500 and it is the BEST thing I ever did to my truck. They re-engineer and beef-up many, many parts for their trannys. All their re-engineered parts are Made in the U. S. A. by American Machinists in ATS's own machine shop. Here is a thread I posted when I had mine done. I've got 75,000 miles on my ATS Stage IV trans now, and it has never missed a shift or given me any problems whatsoever.



https://www.turbodieselregister.com...?threadid=40441&highlight=experience+with+ATS

 

[Howard Durand]

I think he wants to try a new TPS first. If so, I have no idea where to get one other than DC or Cummins.

I got lucky a couple of years ago. A member had some new ones listed on the Classifieds at $60 each. I wish I had bought a couple more.

If your TPS is working smoothly but the voltage reads low at idle position, you can add a variable resistor in the ground leg and bring it up where you want it.

PM me if you want more information.