Throttle position sensor

[rfitzgarrald]

Here's the problem:

If I maintain a steady speed under 52mph & no extra pressure on the accelerator I can feel the transmission start to search between od & 3rd. If I give it just the slightest amount of pressure it kicks down to third and stays there until I either let off slightly or get mad and mash it to the floor and it shifts to od on its own at 62mph.

transmission temp gauge reads- 150/160*, 124,000 miles on the truck.

Fluid is not burnt or discolored.



Am I going to have to bite the bullet and pop for a new tps?, or would someone give me some insight on how to fix it.



Thanks for the replies ahead of time,

Ron

 

[BushWakr - RIP]

HI Ron,



Take a breath bud... . we'll work on it with ya...

First thing to do if you haven't already tried it is go to work on your connections. .

Pull the connector on the TPS, use some electrical contact cleaner, give it a shot of compressed air (I use an air can for electrical stuff from Radio Shack).

Once it's dried out, apply some dielectric grease to it and reconnect.

Do this with ALL your underhood connectors. \

Next I'll send you a "how to" on the TPS if you like.

It's a work in progress because every now and then I need to add or adjust some of the info but it works pretty well when the issue is "out of adjustment" problems.

You'll need a DC volt meter, a straight pin or paper clip with on end sharpened a bit, a 10 or 11mm (I think) combo wrench and some patience.

I have to go to my home PC to send the text file to you as I don't have it here at the shop.



bob

 

[dan brooks]

Bob - If you could forward that to me, too, I'd appreciate it. I've been having an issue with OD as well, and adjusted the TPS to . 7 volts at idle a few days ago - we'll see how it works after a few days (it was at . 36V before I messed with it). I tried setting it at the 1. 0V the FSM calls for and it made things worse.



Thanks

 

[Greenleaf]

TPS Adjustments

I followed Bob's directions to adjust. When I purchased my truck it had a new TPS installed. Was way off! I literally had no OD. After the initial adjustment, things began to take shape for me. Once I became acquainted with how it works I began to tweak it with the use of the 10mm wrench only. The "seat of my pants" if you will. Things are looking good now



Greenleaf

 

[BushWakr - RIP]

Ok, when I get in tonight I'll send it along to you guys if it's not too late.

In this case the "manual" doesn't have a clue ... ... . been there, tried that, got the T-Shirt and the video... ... ya right... ...



bob.

 

[powerwagon440]

bob could u also send it to me! my 93 has the same prob as everyone else and if i get my 91 going im sure it will have the same deal! thank u very much sir! Andy

 

[RamAZ]

rfitzgarrald. I took the top of the TPS off and sprayed down with contact cleaner and re-glued top back on. I also cleaned the connector with contact cleaner and used the diaelectric grease.



I reinstalled the TPS and set the voltage at . 7 to . 8VDC and things still wern't quite right. I looked at the speed sensor and found the nut cracked, Replace it and all is well now. That was 60K miles ago.



The TPS can be frustrating but other things like the speed sensor and trans temperature switch can hold off OD also



Good luck.



Jim

 

[Clarkoh]

TPS Adjustment

I bought my '92 new. From the minute I drove it I was unhappy with the constant downshifting from OD to 3rd with even the slightest additional throttle pressure. A friend at the Dodge dealer ordered a new TPS. We changed it and adjusted it by the book. Same old!



I gave it about an 1/8 turn adjustment and now it acts like I like it! Stays in OD, unless I hammer it or push the OD lockout! 3rd gear should be in mint condition. As it goes up through the gears, it grabs OD as soon as possible & stays there. A diesel should grunt, not scream for a higher (lower numerical) gear! At least according to me!

 

[BushWakr - RIP]

Ok guys, it's on it's way right now... .



As I noted, this will help if it is a TPS "out of adjustment" issue.

It will not help if you have a bagged TPS or if you have issues with your speed sensor or other component.

That will take a bit of time to diagnose if this fails.



Keep us posted on your results... what you find may get added to the TPS file for the next guy who has trouble...



Pastor bob.

 

[rfitzgarrald]

Oo. Thanks for all the info. Will probably get to it this wknd.



Bob, I sure would like that info on setting the tps, either pm me or send it to -- email address removed --



Thanks again,

Ron

 

[dan brooks]

Thanks, Bob - got the instructions.

 

[GTX_Joel]

Hi, I have that problem just developing. It has done it a few times recently. May I have a copy of the instructions too? Thanks, Joel

 

[Greenleaf]

TPS Instructions

The afore mentioned instructions are located on page 48, issue #40. If that helps anyone.

 

[rfitzgarrald]

Oo. Thanks Bushwakr for the info, very, very helpful!!! Oo.



As you can see I'm as happy as a pig in mud. Adjusted the tps yesterday and the at rest voltage was . 583vdc and wot voltage was 3. 63vdc. I lowered the at rest voltage to . 462vdc and that brought the wot voltage down to 3. 42vdc.

Test drove it, holding it between 40 & 50mph, felt no hunting & searching between 3rd & 4th and vice versa.

While holding the speed at 40 I gradually depressed the accelerator and to my surprise Oo. , no kick down to 3rd, just a nice steady pull. If I mashed it to the floor at 40, it would kick down to 3rd, but the second I let off it would shift into od.



This group of members makes me soooooo happy!!!!!

Thanks again and I hope this may help someone else,

Ron

 

[BushWakr - RIP]

Hey Ron,



No problem... if I hadn't gotten help from others I wouldn't have it to pass on here... just like all the rest of the "ole horses" in here... .

Now you just need to "pay it forward" for the next guy who needs it.

My suggestion is to start a "diesel text or document" directory and save these things for future needs...



Pastor bob.

 

[GTX_Joel]

Hey! I found it in issue 40 of the TDR. Thanks!