cruise control/TPS question

[michigandon]

Does the cruise control on a '93 utilize the signal from the TPS?



Reason I ask is because I think I have all the stuff from the donor truck to make the cruise work on my project. However, the TPS on my 92 W250 gave me so much heartache and sorrow that I have been seriously thinking about hooking it up to a switch and shifting it manually. Can I do this and still have a working cruise or not?



Enquiring minds wanna know.



Don

 

[Greenleaf]

Don,

Yes it do. The switch is one option... . and another would be to manually set the TPS in one position and lock it in place like Phillips5 did.



Still have working cruise? I think so.



Scott

 

[phillips5]

My cruse has not worked sence I bought the truck that was before I riged the tps. I don't think the cruse needs the tps. Some day I will dig into my cruse problem and get it working.

 

[michigandon]

I should clarify a little. I meant to say that I wanted to control the OD with a toggle switch. But if I can get power directly to the cruise by jumpering around that POS TPS, that's be cool too.

 

[1stgen4evr]

POS TPS,

I second that. Can't believe that cruise absolutely requires a TPS. Trucks with manual trannys don't have a TPS but do have cruise.



Had a bucket truck that had a very strong spring against the throttle because of mechanism to speed the engine from the bucket. We made a prop stick to apply cruise control.



Been thinking about doing the same to the 93. Fix a length of broom handle the right length to hold the acclerator to the right place. Rig it so you can cancel it by tiping it out with your toe.



I am not sure why these VE pumps have such a strong spring. My old 58 Mack had almost no spring on the throttle. I do know that long trips will wear out the leg.



1stgen4evr

James

 

[cerberusiam]

The cruise control should use the signal from the speed sensor not the TPS. I think it is fed thru the PCM then to the cruise and TPS. The TPS not working should not affect the cruise operation but sometimes it is tough to tell what goes on with the PCM signal.



James, the VE pumps don't have a strong spring they a very light spring on the throttle. You may have a bind in the linkage somewhere that is causing the stiffness. Mine was the same way till I took it apart and fixed the problems. Now it is nice and light and easy to hold speed with.

 

[MMiller]

James



Can't remember if you have an auto or not, but the kickdown adds alot of tension to the fuel pedal too. I agree with above, my manual throttle is very easy, almost too easy off road. My 90 with the auto is stiffer.



Michael.

 

[phillips5]

I think I herd that very often that the cruse problem is the pcm.

 

[cerberusiam]

The kickdown cable should not add a lot to the feel of the throttle pedal. It should be practically unoticeable whether it is installed or not. What I remember is the 91 manual pedal was stiffer than my 92 auto pedal after I found the problems. A lot of stiffness problems happen with the kickdown cable and the bell crank assembly and can be easily fixed.



My cruise has quit 3 times. The first 2 times it went to dealer and they replaced parts and finally said PCM is bad. Both times it was bad connections in the harness that caused the problem. I haven't fixed the 3rd time yet for lack of time. From the info I have gathered the PCM is responsible for picking up the speed sensor output and feeding that to the needed components. If the signal is bad from speed sensor cruise and TPS do not funtion correctly. However, the cruise has inherent problems with the buttons and connections and most of the time it is not the PCM causing the problem. I have had a PCM go bad and periodically drop out. I lost OD, cruise, charge, and speedo when this happened and it would come back as soon as the PCM started working right.

 

[1stgen4evr]

Heavy spring

Maybe I am getting week in my old age or maybe I need to look at the other things. I changed the kick down cable once on the automatic and I still thought it was awfully hard to press the accelerator. It is the same on the manual. Guess I will have to unhook the pump and trace down what is really binding.



Michael, I have two ODs a Getrag and a 727. I mostly drive the manual for the sake of fuel mileage.



My experience with the TPS is all negative. One reason I bought the 89 was to duplicate the system WITHOUT the PCM. Again, the manual has no TPS so I don't think it is a must for cruise.



Thanks all, I feel like I have stolen this thread but I appreciate the info.



1stgen4evr

James

 

[dpuckett]

James, yes you are getting old :-laf; try driving a 6. 9/7. 3 IDI Ford, and the CTD accelerator will seem mushy. BUT, there is sometimes a spring going from the throttle bracket on the pump to a bracket on the timing cover to add a little stiffness to the go pedal. My current one has 2 springs intertwined together. I've had 4 trucks that had the sprign, or something like it; 2 had nothing besides the pump internal spring.



I dont think cruise is controlled by the PCM. The early trucks w/o a PCM had it, along with manual trannies. However, if the TPS is acting up, it might send a disable signal to the PCM (??). Check the tension on the clip coming from the servo to the throttle brakcet. Mom's had a keeper fall out, and the cruise didnt work. DIdnt find it out till I got my next truck, and got to looking. PUt a paperclip in there, and it has done ok for 3 years.



Daniel

 

[cerberusiam]

Daniel, I would agree with you but for the fact it is not called "cruise" control on a stick truck but rather called "speed" control. If memory serves me there is a difference in the way it was implemented and controlled and that differed between years. I can tell you on my 92 unequivocally the cruise is hooked to the PCM and if it doesn't funtion correctly cruise no worky right. All other years its a toss up but I think it would be a good guess the trucks that have the integrated electronics have the same setup. Of course you realize that the 92 parts manuals still listed the Voltage regulator as part of the charging system. Either it was a bad book or a bad parts person. Go figure.

 

[Marty1]

If anyone ever needs a new PCM I have a brand new one sitting here in a sealed Mopar box for a 1993 Auto.

I had PCM problems with my charging system & bought a new PCM but decided to eliminate the PCM by installing an external regulator & rewiring the charging system.

I've since sold the 93 auto & have no use for it.

 

[tugboatphil]

Marty,



Checked out your gallery... . Awesome!! Both rigs!! More pics, please???

 

[Marty1]

Phil,

Thanks!

The Yellow one or the red one?

The Yellow Power Wagon is my friend Jonas's. We both collect them.

Here's the last one I restored & I'm working on an orange & black one right now. #ad

 

[tugboatphil]

Oo.



That one is my new wallpaper!!



Ever put a CTD in one of those?

 

[Marty1]

Phil,

No room for a 6BTA. The cab on these is real small & the engine would come way beyond the firewall.

There is a local guy that has stretched the hood & fenders on one & mounted it on a First Gen chassis.

Several guys have installed 4BTA's & that works real well.

Nascar Mark has a 4BTA we're trying to talk him out of!

 

[Marty1]

Here's more pictures of the Blue WDX with 41" tires & some custom wheels I build. 1946 WDX Power Wagon