Engine/Transmission (1994 - 1998) Torque converter unlocking/locking while towing

[Prostock]

I'm out here at the Mopar nationals, and my stock 94 auto trans's converter started unlocking/locking on the way out. The you can hear it and see it on the tach.



There is only 7k miles on the trans, but it is out of warranty due to time, and it was done to by the previous owner.



Will this thing make it back to PA, and is there anything I can check here?

 

[Joe G.]

Tom,



Get some contact cleaner and soak the TPS where the shaft comes out. Work the throttle linkage back and forth as you do it. That just might help or even fix it.

 

[Prostock]

I don't have my service manual with me. Can you please describe where the TPS is.



Would radio shack sell contact cleaner?

 

[shendren]

just buy brake parts cleaner... .



find the tps on your rig and get familiar with it... . i had too.....



then, check the voltages..... see below... .



THEN when all of that doesn't work..... try jerking the frappin wires out of the wiring harness back about 2-3 ft. that should do it... ask me how i know after spending $1300 on parts one could do this and fix this pos transmission problem!!



this was posted by bill kondolay a while back... .



TPS Adjustment

The throttle position sensor, shift lever, and throttle valve cable are critical to proper operation of the transmission. If one or more of these are out of adjustment or if the TPS is noisy, shifting will be erratic. Before performing any adjustments, check the transmission fluid level and sniff the fluid. Do not make any adjustments until the fluid level is correct, and burned fluid has been replaced.

The service manual says to adjust for 0. 8-1. 2V at idle. On many trucks, this voltage is too low, resulting in TCC chatter at moderate throttle loads. The TPS is not officially adjustable but the mounting holes are slotted and the body can be rotated slightly. Adjustment is relatively easy, and requires only a digital voltmeter and a few hand tools. A little adjustment goes a long way...

TPS wire color code:

• Black = ground

• Orange/dark blue stripe (center pin) = signal

• Purple/white stripe = 5V power

Testing and adjusting the TPS:

1. With the key "OFF", unplug the connector from the TPS.

2. Turn the key "on" and insert DVM probes into the connector to reach the connector pins. Short pieces of wire or paper clips can be used to extend the DVM probes for reaching into the connectors.

3. Read from the purple wire to the black wire (these should be the outside pins). Power should be 5V with the key "on".

4. Turn the key "off" and plug the connector back onto the TPS

5. Insert the leads from the digital volt meter into the back of the TPS connector. The DVM negative probe goes into the back of the connector cavity with the black wire. The positive DVM probe goes into the back of the connector cavity with the orange signal wire.

NOTE: Push the probes into the rear of the connector until the probe tips reach the metal connector pins.

6. Loosen the TPS mounting screws

7. With the engine off and key on: Adjust the TPS position for 1. 2 to 1. 5V on the signal wire with the throttle at the idle position - more voltage makes more TC clutch pressure, too much will set a fault code. Often, adjusting for 1. 4 to 1. 5V at idle will cure TC clutch chatter under light load conditions. NOTE: The factory setting is 1. 2V max, so proceed carefully.

8. Tighten the TPS screws, slowly open the throttle to the WOT position and then return return to idle. Watch for voltage jumps - the voltage should change smoothly from the idle value to at least 3. 5V at WOT (5 volts is all you should be able to get)

 

[Joe G.]

Prostock,



The TPS is the black gadget on the end of the linkage tangle on the side of the injector pump. It has a three wire connector going to it. The contact cleaner works most of the time. Sometimes it doesn't and you have to do more. You can get the stuff at Radio Shack.

 

[Prostock]

Thanks for the responses. I'll try your suggestions when I get back home.



A friend bought a 93 extended cab CTD out here at the Mopar nationals, so they're be a new member pretty soon.

 

[shendren]

pull those wires out. it don't cost anything!!

 

[Prostock]

It ran flawlessly coming home from the 'Nats. Should I even bother?

 

[Joe G.]

Adding cleaning it to your list of things you do when you service it and you should be ok. Mine has been working for 155K miles and that's all I do for service.