Engine/Transmission (1994 - 1998) Help!!! Every known problem with my truck.

[Swamp Donkey]

Where to start... ... ..... I just installed a different valve body in my truck. There should not be any problems with that, other than the fact that I am a meathead and could not get the kick down cable adjusted. That is now all fine.



I have been trying everything possible to get my TPS working properly. I have taken it apart, cleaned it, checked the voltages, and re-wired it outside of the factory wiring harness. Now this is where things get interesting. First I re-wired the orange/blue wire from the TPS with no change. After driving with my truck hunting/flaring/slipping shifts I then re wired the purple/white wire from the TPS. I tapped into these on the bundle of wires that goes to the PCM closest to the engine. Little did I know that there are more than 1 p/w and o/b wires going to the PCM. After doing this, I now notice that tach does not work and that now my alternator is not charging. That leads me to the crank position sensor. Are these 2 somehow related? The transmission seems to be in 3rd gear limp mode now. I can manually upshift, and select gears that way, but my OD does not work. I have been searching the archives for hours on kick down adjustments, tps, cps, alternators and every other issue I seem to be having. Where do I start? I need help. Bad.





And for the first time in 5+ years that I have had my truck my FSM is not with me. I can' t find a cps anywhere at a dealership. Already bought a TPS and have not installed it. That also irks me, bought it from NAPA for $250 clams, and you can see right on top where it had been taken apart just like mine and epoxied back together. Reman from NAPA Has anyone ever had all kinds of problems from an eratic alternator? All these problems seem way to fishy to me. On a side note, I cleaned up all the ground connections on the battery added a 10g wire from the battery right to the PCM. Right now the transmission is acting OK. I manually upshift from 1-3 and there is no hunting, flaring, upshifting, downshifting and everything inbetween. No OD though.



Ever since my tach and alternator have stopped working, my transmission has been giving me much less greif. What do you all figure? Oh and to make matters worse, I need my truck for work ( I get paid to use my truck) on tuesday and it seems like there is screw all around for a cps and alternator in town. Parts are hard to come by!

 

[datablitz]

did you put the new tps in after you rewired it? or before?

 

[Howard Durand]

Swamp Donkey,



I think, on your truck, you will find that one of the wires you tapped into provides voltage to both the TPS and the engine speed sensor or what you call the crank position sensor.

Did you just tap into it at the PCM or did you cut the wire?

All of the things you say are not working are directly associated with the engine speed sensor.

It sounds to me like you have opened up either the voltage source to it or the signal return from it. Either way you have to get that straightened out.

If nothing else, put everything back the way it was and start over.

My truck is a 94 and my wiring is different than yours so I can't tell you which wires you should be cutting or tapping. If you don't have a manual with you maybe someone will chime in here and help you out.



If you have a volt meter you can check the middle wire going to the engine speed sensor (on mine the wire is orange). It should read about 8 volts.

If you have voltage then the problem would be either an open signal wire or poor ground.

All of the engine sensors ground at a common point at the front of the engine next to the #1 cylinder valve cover on the driver's side.

I really think you have somehow cut the voltage supply to the engine speed sensor.



To properly install new TPS wiring you need to tap into the existing wires at the PCM, run the new wires outside the harness to the TPS, cut the existing wires loose at the TPS and splice in the new ones. That way anything else that is fed from the existing wires will still be connected.

 

[Swamp Donkey]

Howard,



I think you nailed this one. I just chopped the wires and left them open. I will re-connect the wires and "splice" into them. Things are looking up this mornig.

 

[Swamp Donkey]

Well..... just got back from another short test drive. It is still being and ignorant pig. I think I will put in the different TPS, and if that doesn't fix it I will hook up my mystery switch again. I wish I could take everything electrical with my transmission and smash it into 10000 pieces with a 10lb sledge hammer.

 

[Swamp Donkey]

What is happening now is it is like the transmission is comepletely slipping out of gear. Almost like it is supposed to be locked up, but nothing is connected. Driving along and the tach will zing up to 3000 rps with no connection to rear wheels. Pop it into N and baby it for awhile and then "something" is happy and the transmission feels just as strong as usual.



Please tell me I can hook up my mystery switch and all these problems will be gone! I am hesitant to do this, because I have eaten up 2 pcm's already. Still got one of my old eaten up pcm's. Both VB have done this flaring thing, so chances are that it is not inn the VB but with my lovely electrical system.





All this is still happening even after the "new" tps. this temp sensor is it the same one as the gov press sensor? Or is it the one by the shifting linkage?



Good golly I am in a world of hurt.

 

[Swamp Donkey]

Just doing a little more thinking. Should I have spliced into the orange/blue wire as well. I also just chopped that one. Could that be part of my problem?

 

[datablitz]

i that you should put all the wires back to the orig. configuration and try it again and rather than running new wires, test voltages on the wires, and such.

 

[Howard Durand]

Swamp Donkey,



If your TPS wiring is the same as mine, the orange/blue wire carries the signal from the TPS to the PCM. If it has been cut and not re-connected, you are still operating without the TPS input to the PCM.

 

[bmoeller]

Is the return spring still attached to the throttle valve on the transmission end? If it is missing, or hanging loose, it will cause low line pressure. When mine was missing, it had VERY mushy shifting, and felt like it was slipping. After replacing it, and disconnecting the batteries for a short time, it was back to normal.

 

[Swamp Donkey]

I would like to thank everyone for their help and tips. I tried alot of them and made about 10 calls to Bill K. For the last 5 days I had one heck of a battle with my transmission and it won. I took it to the dealership. It is not all bad, I talked with the tech that will be working on my truck for quite some time and feel confident that he can help me out. Even said he wants to talk with Bill. Gives me a little bit of a warm fuzzy feeling!



A donkey can only do so much lying on his back with big eskimo mittens on his hooves in -20 c temps with a wind. First time in the last 5 1/2 years that I have had my truck, it has left me walking. Kinda bad since I just got a contract 3 months ago to use my truck for work. All is not lost, my Mom's Dakota is pinch hitting for the old goat.



I'll be back in 3 weeks... ... ... that is when I get out of the bushes from work. Probably should stay in there a month, paying dealership rates... ...