throttle postion voltage : V-Twin Forum: Harley Davidson Forums

ATTILA · 07-11-2007, 10:40 AM

can someone please explain how to adjust it and what effect it has on tuning ???

HDMD88 · 07-11-2007, 11:53 AM

Quote:

Originally Posted by ATTILA

can someone please explain how to adjust it and what effect it has on tuning ???

This is how I did a 48mm throttle body I had done by Gerolamy.
I removed the soft plug to access the throttle plate adjusting screw, opened the throttle plate till a voltage of .35 to .4 was reached. This is done at 240 to 260 degrees then I set the IAC to 40 steps.

This setting will effect throttle position as far as the tune goes. I think you can find this info in the Harley electronic manual

merc1100sc · 07-11-2007, 01:05 PM

A lot of times you may have to break the plastic tab off the back of the TPS and elongate the mounting screw holes so that you can turn the TPS to get to the desired voltage and then tighten it down. Not an expert but from what Ive learned right around .4v represents 0% (idle) throttle position. If you're at say.6 volts w/ the throttle blade closed, the ECM will think you're at say 1.5% throttle and it will throw the whole spectrum out of wack.

kelly · 07-11-2007, 03:38 PM

Merc and Doc

First things first--Very Good to see you back Doc--as always, your posts shine with brilliance and glimmer of genius!

What an unexpected surprise to see this topic come up--my diagnostic codes keep displaying the TPS error and I get the stumbling/low idle. Picked up a new TPS at a dealer outside of Columbus, Ohio, on my way through.

Merc--before I plug and play the new TPS--I want to try your method--which direction are you turning the sensor--cw or ccw? (not to slight Doc--I just don't have a dremmel to cut a slot on the throttle blade screw so I can turn it).

HDMD88 · 07-11-2007, 03:54 PM

Kelly good to see you here too...
If you haven't had the throttle plate removed or a modified throttle body or a new throttle body installed there shouldn't be any need for you to adjust the the throttl plate screw.

merc1100sc · 07-12-2007, 08:11 AM

Listen to doc's advice before mine. Im just learning myself, but, to answer your question, turn the tps clockwise (if your standing behind the t/b facing the front of the bike) to reduce the tps voltage.

kelly · 07-12-2007, 11:36 AM

Gentlemen, Thank you very much. Looks like I will have to install the new TPS because of a "NO rSP" on the Diagnostics after clearing the codes--great stuff to know when I plug and play and then check for proper milllivolt readings if needed.

If your ever in need when you role through Kansas--please feel free to stop in grab some food or rest.

GRock · 07-12-2007, 06:15 PM

I have to jump in here for a second guys. The best way to adjust an out of range TPS is by adjusting the TPS, NOT the throttle blade! When you open or close the throttle blade you are adding or subtracting air that the IAC stepper is already programmed to control. If you are off a tenth or two in the voltage, then no big deal, but anything more than that and you need to slot the TPS so that it can spin a bit on the mounting screws and then make your adjustments. Harleys fix is for stock or stage one mod is that they are assuming is a minor variance or noise in the rheostat. Anything over and above that requires either a new TPS or adjustment of the TPS in it's own mount.

G

badmotorscooter · 07-12-2007, 06:22 PM

What does "NO rSP" mean?

bms

YankeeBob · 07-12-2007, 06:25 PM

No Rear Spark

badmotorscooter · 07-12-2007, 06:47 PM

Thanks for the reply. My bike says "NO rSP" when I run diagnostics. My bike runs, but it does seem to miss a beat every now and then when idling. Every once in a while after riding awhile then stopping, it will hestitate right after firing it up and riding off. I assume this is because of the rear spark issue. What could be the cause of "NO rSP"? All responses will be appreciated.

bms

CHIPMAKER · 07-12-2007, 06:59 PM

How would one adjust the throttle blade, and then the tps? The dummies at the stealer said they generally adjust it when doing a big bore kit, I think it is out of whack?

HDMD88 · 07-12-2007, 07:57 PM

Quote:

Originally Posted by CHIPMAKER

How would one adjust the throttle blade, and then the tps? The dummies at the stealer said they generally adjust it when doing a big bore kit, I think it is out of whack?

They shouldn't touch it unless the bike is stalling at decel to 0 TP

Woody218 · 07-12-2007, 08:01 PM

Quote:

Originally Posted by badmotorscooter

Thanks for the reply. My bike says "NO rSP" when I run diagnostics. My bike runs, but it does seem to miss a beat every now and then when idling. Every once in a while after riding awhile then stopping, it will hestitate right after firing it up and riding off. I assume this is because of the rear spark issue. What could be the cause of "NO rSP"? All responses will be appreciated.

bms

I had the same error code when the MAP sensor went south. The dealer replaced the sensor, and the problem was solved.

hdmarsh77 · 07-12-2007, 08:11 PM

Quote:

Originally Posted by badmotorscooter

Thanks for the reply. My bike says "NO rSP" when I run diagnostics. My bike runs, but it does seem to miss a beat every now and then when idling. Every once in a while after riding awhile then stopping, it will hestitate right after firing it up and riding off. I assume this is because of the rear spark issue. What could be the cause of "NO rSP"? All responses will be appreciated.

bms

That actually means "No Response". Try it again with the Run/Off switch in RUN, like you would to start it.

Hold the odo button in and turn on the ignition switch.