Throttle Position Sensor

[Sexagenarian]

I Did a search and found this older posting on the TPS:

 

Anyone here ever tried to adjust the throttle position sensor on a 2nd gen (or even just check the closed throttle measurement)? I think I found another significant error in the shop manual, but I would like to compare notes with others who may have already gone there.

 

Page 6-13 of my shop manual describes how to calculate the proper maximum resistance of the sensor in the throttle fully closed position (typically around 700 ohms), then they instruct you to measure this resistance between the yellow and blue wires. Well, the resistance between the yellow and blue wires is HIGH in the fully closed position and goes down as you open the throttle. You get the correct low resistance with the throttle fully closed when measured between the yellow and BLACK wires.

 

I had to separate the carbs which of course means removing the TPS. You are correct V7Goose, something is wierd with the Royal Star Clymer manual also. Like V7 mentioned, it is also backwards. I can't find anything definitive which corrects the manual so here is my POA (plan of attack) unless anyone can correct me .. I will compute the math mentioned in the manual to find the high/low range for adjustment. But I will be reading the Yellow and the Black/Blue wire instead of the yellow and the Blue wire. I will then adjust the TPS for the adjustment range derived from the previous steps in the manual utilizing the readins on the yellow and Black/blue wires instead of the solid blue wire and yellow.

 

I also removed the darned security screws, lockwasher, flatwasher combonation holding the TPS in place and replaced them with an Allen head, lockwasher, flatwasher combo.

Thoughts anyone?

[Sexagenarian]

lacking any responses to my post just above this, I spent a couple hours researching on google. Always remember, Google is your friend !! Here is what I found on setting the positioning for the TPS module: This is what the Clymer manual should have had in it to begin with !!

 

The correct way to position your TPS sensor

 

--Wayne

[Condor]

Gotta question?? The link takes me to a Road Star page and the schmatic shows a different location of the TPS. So... Would there be a difference from the Road Star readings and those for the RSV since the TPS controls the timing curve... or is that something that's converted in the TCI?? According to Goose the resistance goes down not up from idle for the RSV??? This is interesting as I'm in the process of swapping out the carbs on the '99 and figure as long as I'm in there I might as well make sure everything is Kosher while they're off.....

[Sexagenarian]

Condor, I am so sorry for not finding that another contributor (you) had responded to this thread until now. What I finally ended up doing was setting my TPS to 700 ohms after going through the mathematical formulas in the Clymer Manual. But to get there, I had to set it to 700 ohms and then put the tachometer on spark plug wire #1 and adjust the idle to 1000rpm's.. Once the idle was adjusted, then I went back and re-adjusted the TPS back to 700 ohms again. From reading various forums, I found one whereby they swear at a value of 675 ohms for that setting. But I settled on the 700 ohm value based on the formulas in the manual. I never did dial in 675 ohms to see if it was better than the 700 ohms...cheers!!-Wayne