cheverge

I have a 93 2-wheel drive. I have done this by pass, it seems to have helped some, but my truck is still kicking in and out of overdrive, mainly when there is a change in the gas pedal, if im cruising in overdrive and just barely accelerate or decelerate it kicks out of overdrive. Thanks ahead for any info guys.

bulldog17w

I've got this problem too... I have to step hard into the pedal around 50+ then let off the pedal and ease back into it to get my overdrive to kick in, but the minute i try to climb an upgrade or step on the pedal a little hard it kicks right back out... I was wondering if something is out of adjustment??

thanks

Tuckerdee

Sounds like your TPS needs adjusted. There's a procedure in the sticky area.

bulldog17w

thanks tuckerdee.. I also forgot to mention that my speedo is about 10 miles per hour slow, so i was thinkin that might of had something to do with it also? Is there an adjustment for the speedo?

Tuckerdee

Fill in your signature so we know what you've got under the hood. And welcome to this little community.

Yes, that will affect how and when your OD shifts. The computer looks vehicle speed, throttle position, and some temperatures to determine when the shift happens. That's the beauty of the potentiometer upgrade. You can dial in your shift point.

There's no adjustment. You can change the gear size in the tailhousing of your transmission. It's not hard. Do you have larger than stock tires?

bulldog17w

sorry it's a 91 intercooled 12v

nilezy

Gday all,

I have just done this mod.

This is what happened before it all went pear shaped:

I bought the truck in LA, California. I had the transmission rebuilt, as it was slipping in 3rd gear. Box was stuffed when the shop opened it up, so they rebuilt it with all the updated parts from the TSB from Dodge. I had a Mojave HD torque converter in the truck already, but since it was full if metal shavings, they replaced it with an exhange HD torque converter. I don't know what brand name, I didn't get to the shop before it was put back together. I drove it around LA for 1200 miles, truck drove flawlessly. I left LA, and as soon as I got about 800 miles out, the shifting strategy changed, and all the way up to Vancouver, Canada the TQ lock up would disengage randomly. I thought the brake switch light was faulty, so changed that, but it didn't fix the problem.

Anyway, two weeks ago I towed a 1.5 tonne Yacht from Vancouver to Seattle and back without a problem, the TQ was locking up fine, and holding. I pressure cleaned the engine bay last week and after that day I came to the point where I would drive on the freeway and the O/D would not select, and the TQ converter would not engage. I guess I got some moisture into the TPS for it to corrode like it has. If I pressed the O/D off button, it would not lockup the TQ converter, and the cruise control would not work. I checked the TPS and it was gone. I pulled it apart to try and fix it, but the resistive film surface had corroded away.

So I thought that the mod would fix my problems.....

The truck will now shift into O/D, but only once has it locked the TQ converter on the highway doing 100km. It will not lock the TQ at all now down around 50-60 km/h. Before, it used to lock as low as 50 km/h and hold going up a hill, and only let go when you pushed the TPS to 80-90%. The cruise control works now at 70+ km/h.

The other strange thing is that the error code sequence will flash code 24 (TPS) twice in a row.
I get the usual code 12, then 24, then 24 again, then 55.

I find this odd. How do I clear the codes on the PCM?
The transmission has not faulted on the whole trip other than the TQ lockup and now the TPS going, stopping it from changing into O/D.

Could someone please check a working TPS and tell me the resistive value? between the ground and the +5V line? between the ground and the signal with the TPS at half way?
I'd like to put a working TPS back in place of the original, but i'm not paying $200 dollars for a potentiometer!!! I'm even thinking of putting a pot on the accelerator pedal instead of the injector pump.

Anybody care to speculate?

Cheers,
Nilezy

wannadiesel

You might want to ask the 2nd gen guys about it.

nilezy

ok, cheers, didn't realise I was in the 1st Gen topic area (Newbie)

Cheer,
Nilezy

wannadiesel

No prob, there just may be differences in how your later model PCM operates and we wouldn't want to give you misleading or useless info.

cumminsdriver635

Nilezy: I have this on my 2nd gen, and the TC lockup MPH goes up as you adjust the **** for OD to come in later. My TC locks like clockwork at 50mph with my OD set to come in at 45mph. You may be having problems with the transmission? I know on mine if i dont have the POT set right, I dont get overdrive or lockup, so id make sure its adjusted right. You do have the correct POT, right? Putting the **** in the middle is a good place to start the adjustment.

Eric

nilezy

Hey,

Yep, I have a 5k pot, 1/2 watt

I have been going off the output voltage, and setting it to around 1 volt for idle, and turning it up to around 2.2 volts for accel. and then backing it off to 1.8 volts up around 100 km/h.
I'm using my multimeter to monitor the output voltage of the pot.

I only got the T/C to lock once, and never again has it locked up. My transmission is fine, and works for everything else, even hard accel. Like I said, its only got 2000 miles on it since its been rebuilt.

Cheers,
Nilezy

Ramdriver15

i have a 96 and this isnt working out to grand. i have the 5k ohm pot 250vdc, 1/2 w. no luck when in use. only shifts at 60+ no matter the settting
any help be much abliged.

Tuckerdee

I'm betting you could have the wires hooked up wrong. If you have 2 of them reversed you could be measuring the resistance of the pot the entire time. IE. the computer always sees 5k ohms instead of a changing value. Check the wires to make sure you have them hooked up correctly. Moving them around won't hurt anything...I don't think anyway.

Ramdriver15

i have the middle wire to the middle post, and the outer two didnt matter all that much i thought