Engine/Transmission (1994 - 1998) 94' 12V Auto Trans Shifting Probs

[JLerch]

Hello All,



Here we go... . I have a 94 2500 4x4 reg cab with the 5. 9 (obviously). 201K mi. I had the transmission rebuilt last year. The truck has been parked ever since (long story... ... ) Anyway - 1st gear runs up around 2200 rpm and will sit there for a couple seconds before banging into second. It is very annoying...



I had replaced the TPS after the trans was fixed thinking it would solve the problem, it didn't.



First - has anyone dealt with this?



Second - Does the throttle linkage need to be adjusted to make the TPS work properly?





Thanks - I apologize in advance if this topic has been discussed. I did not have time to search the site.

 

[mjs]

I'm not certain but i think the tps is just for converter lock up . Maybe the cable to the trans is miss adjusted or frozen and not returning . Also was this always a problem from the get go . Maybe the govnor or bands are miss adjusted . Just some food for thought. Mike

 

[tp0d]

You have a hydraulically operated transmission. Something inside the valve body is not sensing the proper pressure, and shifting at the wrong time. I dont think bands could do this, but I`m no transmission expert.

I would take it back to your builder and start there.

Definetly not the TPS.

good luck

-j

 

[JLerch]

So the trans has no electronic input from the computer ? Aside from tuning the O/D off?

 

[BigPapa]

JLerch,



I experienced the same problem with mine before I replaced it. As stated, your transmission shifts are hydraulicly controlled except for overdrive and TC lockup. I was told by my transmission man that there is a seal in the transmission, I think he called it a front lip seal, that will leak pressure internally, and will not allow enough pressure to shift. He told me that it would eventually get to the point where it would not go into reverse, and that I should be prepared to rebuild it. Sure enough, I started having problems going into reverse. I would suspect this to be your problem also.



Scott

 

[Missouri Mule]

Is it only doing it from 1rst to 2nd? If it doing from 2nd to 3rd also try adjusting your throttle valve cable.

 

[USMCBay]

Okay - heres your saving grace. I had the EXACT same problem on my '94 single cab 4x4 Auto... it shifts like it has a shift kit in it right. I was told everything from "we don't know... " to "check this and that connection" to "you'll need to rebuild your transmission"...



Poppycock... Heres your fix (I hope). There is a large wire loom on driver side of your engine and its coming out of the firewall and going toward the front of the engine - FIND THE PURPLE WIRE AND PULL IT OUT... this wire (I was told) runs on miliamps (I guess to your transmission?) and after a while other currents bleed over into. I did this and it stopped immediately. Search it out on here - this was back in '02 that some one here told me this and it saved me a bunch of money. I have forever been grateful to TDR just for that fix alone that got me hooked - not to mention the numerous other occasions I have saved a bundle here. Oo.



Give it a try - its free and easy. You will have to cut some tape and some ties but dont cut your wires. I'm 99. 9% its the purple wire because I have rehearsed the story so many times over the years. :-laf



Let us know... I did a double take when I saw your post.

 

[USMCBay]

Hey found it. Oo. I'll copy it below:



_________________________________

Illflem wrote:

i had all of the same symptoms.



2 new tps's - no fix

cleaned the tps - no fix

new pcm - no fix

new trans temp sensor - you guessed it... ... no fix

new gov press solenoid - no fix



pulled the tps wires out of the loom - voila..... fixed.....



_______________________________



CDixon, your TPS is located on the front-left corner of the engine. Looking over the driver side fender, find and follow the throttle cable to its end (will be behind the intake hose). You will also find the end of the cruise cable at the same location (if you have it). There is a black box bolted to the side of the assembly that the cables run too. This is your TPS. It has a three prong cable attached.



ronco



__________________________________

usmcbay wrote:

Listen I really want to thank all of you for helping me out !

illflem it worked ... voila is right. I pulled the wires out yesterday before going home and no more RPM jerks.

I really do appreciate it !!

I drove plenty yesterday evening and for the first time in a long time no RPM varience !!



P. S. Saved the diagram you sent ... much thanks !!!!!!

_________________________________



Another wrote:

My trans was doing same thing. Did all the standard noise fixes including the filter from DTT. No fix. Ended up being the trans temp sensor but I was not getting trans temp light on gauge. 1k ohm resistor fixed it.

 

[BigPapa]

USMC,



What year was the truck you had problems with?



Scott

 

[USMCBay]

USMC,



What year was the truck you had problems with?



Scott

It was a 1994 4x4 Auto...

 

[BigPapa]

Lerch's problem is with the 1st-2nd shift. The TPS has nothing to do with that shift. It controls TC lockup and shifting into OD.



Scott

 

[Skydiver]

Mine was wanting to shift late only when cold. I had the transmission power flushed and it works perfect now. I also removed the check ball in the cooler line.



181k and still pulling. Engine stock. HaHaHaHa

 

[USMCBay]

Lerch's problem is with the 1st-2nd shift. The TPS has nothing to do with that shift. It controls TC lockup and shifting into OD.



Scott

I hear ya' - but mine shifted from 1st to 2nd like it had a shift kit... it stalled and held to high rpm's in first then slammed into 2nd...

 

[KCanepari]

Okay - heres your saving grace. I had the EXACT same problem on my '94 single cab 4x4 Auto... it shifts like it has a shift kit in it right. I was told everything from "we don't know... " to "check this and that connection" to "you'll need to rebuild your transmission"...



Poppycock... Heres your fix (I hope). There is a large wire loom on driver side of your engine and its coming out of the firewall and going toward the front of the engine - FIND THE PURPLE WIRE AND PULL IT OUT... this wire (I was told) runs on miliamps (I guess to your transmission?) and after a while other currents bleed over into. I did this and it stopped immediately. Search it out on here - this was back in '02 that some one here told me this and it saved me a bunch of money. I have forever been grateful to TDR just for that fix alone that got me hooked - not to mention the numerous other occasions I have saved a bundle here. Oo.



Give it a try - its free and easy. You will have to cut some tape and some ties but dont cut your wires. I'm 99. 9% its the purple wire because I have rehearsed the story so many times over the years. :-laf



Let us know... I did a double take when I saw your post.

I'm confused. This was on a '94?? If all the shifts except od are hydraulically controlled how would this fix the problem? I'm having trouble on a '95.