TPS Questions

[Extreme1]

In the 5 years and 117,000 miles that I've had the truck, it has always locked up the TC at 43 mph. This is too low (1,100 rpm) and the truck shakes because it's being lugged. I tried a reflash and that had no affect on the lock up point.



I did a search and read several posts on the TPS but I havent seen this as a symptom. I spoke with Piers yesterday and he suggested the TPS. I tried to adjust it to get the voltage correct (it . 3 @ idle & 2. 0 @ WOT) but about the time I get the voltage to come close the linkage rod came out of the ends. I did consider rotating the switch 90 degrees but then the voltage is way too high and the linkage can't adjust that far.



Other than this, everything seems fine. The voltage transition is smooth as I open the throttle with the voltmeter attached, just low. Does this sound like the TPS? I hate to spend the money for nothing like I did with the reflash.

 

[Strick-9]

You should be able to loosen the bolts holding the TPS and rotate it just a bit in the slots. For me that has usually been enough.



Have you installed the governor spring kit yet or have you tightened the stock springs?



If your governor springs are too tight, you have to reduce your idle set screw for proper idle speed and this will of course lower your idle TPS reading.



TPS at idle should be 1-1. 2 volts at idle and 3. 5+ at WOT if I remember correctly. It's late so I could be wrong.



When you posted . 3V and 2. 0V, is that what you have now or is that what you were trying for?



We can add some throttle travel at the idle setting a few different ways without increasing idle RPM to get your TPS reading right, but I won't go into that if we don't need to.



-Chris

 

[illflem]

Don't fool with your linkage to adjust the tps, it is supposed to be a set length, can't remember the number. If you can't get the required voltage by rotating the tps remove the metal collars that the hold down screws pass though and elongate the holes with a round file or dremal tool, it won't take much. Tip courtesy of Bill K.

 

[Extreme1]

Thanks! The numbers I posted are what I have now at idle and WOT. I haven't installed the a GSK yet but I have one comming. The voltage spec is 1. 0 +/- . 2, Piers said to go for the 1. 2-3. 5 setting.



The throttle seting is 5" +/-1mm. I need to rotate the switch almost 1 (mounting) hole to get the right voltage.



I will pop the collars out and see how much twist I get, file is next!



Thank you gentlemen!

 

[JIM S.]

OK... . how do I test? engine running? where to put tester leads. were did I miss the info on doing this?

Jim

 

[illflem]

Jim, here's the how to http://dodgeram.org/tech/transmission/automatic/TPS_adjust.htm

 

[JIM S.]

Thanks Bill

Jim

 

[Hummin Cummins]

Dont take my word too seriously but if I recall when I did mine, I was told by another member... ... ... old age catchin up cant remember who... ... ... . the 5" measurement on the linkage is an approximate. Just make sure if you change the linkage measurement your still able to get WOT against the stop on the back of the pump.

 

[Extreme1]

Update:

While at teh dyno run at Goerend's this weekend, he was kind enough to loan me a new TPS to try. Very similar readings! (. 3/2. 1). There was another '94 there and I checked his (. 6/2. 8) and his up shifts at 45 mph.



I tried my switch on his and got . 6 volts at idle.



In order to get enough throttle shaft rotation to get the voltage where it belongs, the travel is WAY off. The shaft isn't loose, the ref voltage (5) is OK and the ground has 1> ohm resistance.



I order to "adjust" the switch enough, I'd and up with the holes sloted past the edge of the switch.



Anybody else run accross anything like this?

 

[chucksram]

I need somw clearification here. If I adjust my TPS voltage higher, it will raise the O/D and TC lock-up speeds? Is this correct?

Please help



Thanks

Chuck

 

[JIM S.]

If I adjust my TPS voltage higher, it will raise the O/D and TC lock-up speeds?

It seems like that is the case, on mine it raised lockup in ( D ) from 30 mph to 34 mph, BUT lockup in (OD ) seems to be the same (45 mph) but I havent driven it much since so cant say for sure.

jim

 

[shendren]

regarding building a noise filter......

so, is the sig return wire the black wire? and the sig wire the orange wire? thanks. scott.

 

[JIM S.]

the black wire is the gound wire and the center wire (dont rem the color) is the signal wire and the other one is the 5 volt DC power wire.

Jim

 

[shendren]

yep, i'm all over that..... but they refer to sig and sig return wire in the link? thanks. scott.

 

[shendren]

well i just took mine apart. put it back together. and will try it out after it cures. somewhere i read that someone had a bad ground wire. i have 5v reading on the power side. if i had a bad wire i don't think i would have a good power reading. right? thanks. scott.