Throttle position sensor question? : V-Twin Forum: Harley Davidson Forums

boston rg · 10-24-2009, 09:44 PM

Has anyone seen the % change at idle on the tps?Mine seems to bounce between .5 and 0 at idle.
To replace it the service service manual says just remove and replace it but I have read on here that you need to "dial it in" to get .4 vdc at O throttle-do I need to do that?

boston rg · 10-30-2009, 12:39 PM

anybody?

Ok how about this one- I have a tps on order and will change it once it comes in, the one i have on there now the volt bounce around between .63 and .66- have to assume the new one won't be the same and i am trying to get closer to .40. If i do will that change the IAC steps? Mine right now is about 40 once the bike warms up and from what i read that seems to be a pretty good spot.

ViennaHog · 10-30-2009, 01:13 PM

What year is the engine? If you still have a significant 'float' of the TPS after the replacement, check the throttle plate and the stop screw.
Newer models run between 0.5-0.6 V from the factory. Any running issues at all?

HerkoBagger · 10-30-2009, 02:48 PM

From the readings you posted it appears it's a Delphi cable operated TB. When I see the inconsistent 0.0 to 0.5 at idle it's a sign the TPS is starting to wear IMO.
The exception possibly being with the one piece TB's of 06 and 07 where the mechanical stop would migrate in and out.

If in fact a cable Delphi, do a simple swap out of the TPS and you'll likely see good results.
No need to worry about getting the exact voltages per the book(s). (books voltages differ any way depending which HD book you consult)
As long as your TPS and IAC (steps) have a good relationship all is good.

There's more that can be the problem like throttle cables...
...more in depth discussion here (click)
http://harleytechtalk.org/htt/index....c,17009.0.html

boston rg · 10-30-2009, 03:42 PM

My bad- it is an 06-I bought it used 2 years ago and every now and then it will stall and a little poping on decel. A tuner was at one of the local shops and he was going to do a base run on it and he noticed the tp% drifting. I hooked up the sert in data mode and could see the volts drifting but the % was at 0- I think maybe not as sensitive as what he was using(digital technician) I think.
I will change out the tps and see what the volts are doing-do you know if it will change the IAC?

HerkoBagger · 10-30-2009, 03:47 PM

...do you know if it will change the IAC?

No. IAC steps are based primarily on the blade air gap ie mechanical stop which is 0.0%TPS.

Good tips on what to do while swapping TPS are the link posted in prev reply.

boston rg · 10-30-2009, 03:55 PM

Thanks for the info and thanks for he link- once it gets here i will replace it and post how I make out. thanks

AirGlider · 10-31-2009, 01:52 AM

Boston,

I think you may be remembering posts about the DTT TCFI. This system has you setting the TPS for .4v. To be able to reach that value, most would have to press out the brass inserts and maybe dremel for some extra twist.

Good luck changing it out. Should be a piece of cake.

AG

boston rg · 10-31-2009, 09:25 AM

Thanks AG-

It was in this thread were they were talking about slotting the holes a bit and roating it to get to the .40

http://www.v-twinforum.com/forums/v-...voltage-2.html

boston rg · 11-14-2009, 03:31 PM

The TPS was back ordered, just got it this week and put it in today. Hooked up the sert in data mode the TP volts is right at 63 and not drifting so I hope all is good. My old one and the new one does NOT have any brass inserts, didn't bother slotting the holes after the info you guys gave. Thanks for the input.

relxn88 · 11-14-2009, 06:40 PM

Key on/engine off: 2001 - 2003 tps volts = .4volts 2004 +up = .52volts
1/2 volt either way OK. At least, this is what I've read on the forum. Search Gmr,
Grock, or Doc for more info.