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TPS voltage

G

geo

Well-known member
Dec 1, 2007
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Kamloops B.C.
Always learning, always playing so I have a question.

Does Poo give an altitude and pressure required to test the TPS and set it to their spec?

This is a mildly modified sled not stock.
I've read and been told how important the TPS setting (100th of a volt??) is and I've read about the "bog" too. Mine has a bog I can clutch away but I prefered not to.
I've been using the PCV to tune my sled and I could never quite get rid of the bog using memory and changes at home or the truck.
When I asked for a cure I was told to check TPS voltage or about throttle safety switch thing. All done a couple of times and no success.

So I bought a Boony box ('13 model) again and packed up the PCV. First thing I needed to do was sync the Boony box to the TPS position checking idle and wide open. My no.'s were different than suggested (oh boy here we go again lol) so I asked questions and didn't come to a conclusion really just went for a tuning ride.

The Boony box gives you a display and allows you to change things in the field (missed that). Because I had questionable TPS no.'s I checked these up at altitude.
I found those no.'s were different at 6000' than they were at 1100' and different again at 3500'???

Has anyone ever noticed this? Does Poo change fueling some using TPS voltage changes? If a shop at 5000' sets your TPS voltage will a shop at 100' find it wrong?
This is what my Boony box showed me this weekend.

Anyhow MY bog was a small window of too little fuel at light throttle positions right at 6000 and 6250 (+7% which was a surpise because the ethanol mode made it worse before). And, I was about to take a half a gram off the tip because of a slight backshift issue but a little more fuel at full load 7500 and a little less at 8000 fixed that too lol.

Thanx for making it easy again Boondocker.
 

mtncat1

Well-known member
Lifetime Membership
Oct 19, 2008
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south jordan ut.
altitude does not afect tps ajustment. there is a great post on this in the dragon section, the pros ajust the same way.i did mine with the slp power up harness.it was very easy and did make the sled run better .nice to here from you in the pro section. i enjoyed your posts as a former cat rider:face-icon-small-coo
 
G

geo

Well-known member
Dec 1, 2007
2,170
2,336
113
68
Kamloops B.C.
I'm gonna believe my own eye's for now but my TPS reads lower at 6000' than 1100'. I proved to myself yesterday it is not intake or coolant temp related.

I did the math and it may be insignificant (and I believe this to be true, TPS position is not as important as the map or how you load your motor) but I get a 2.1% lower reading at elevation. That works out to .07ish volts.
At home my voltage at idle is .937 (I was told '13's are set a little higher from the factory) so where I ride it would read .93. Some would say that is enough to require a change and will effect "runability". My sled had the same bog from 1100' to 6000' and I know I created my own bog because of the way I like my clutches to work. Small adjustments to the TPS location would not and did not change a thing. I simply needed to change the map or my clutching.


I've read about the Poo "bog" a lot here. I've read the advice to set the TPS. I've read about having the TPS reset and no change, better, not as good and everything in between.
IMO if your sled starts easy warm and cold and idles close to 1700 1800 changing your TPS won't get rid of a bog. It will just move it ever so slightly to another point in your map and you still won't know exactly where. You would be better off adding 10 or 20 lbs to your engagment pressure on your primary spring to get rid of it.

I have to prove things to myself and sometimes it is easier going from the back to the front.
I installed an SLP pipe and head (it works great KC, nice nice boost in midrange where I ride alot and raised torque peak 100ish so it added powerband too) and immediately had a bog and det issues with my own clutch set-up. It was worse in the ethanol mode so i ASSumed it was a rich spot. Wrong. Poo must do something funny at low throttle positions in ethanol mode.
So I phoned SLP and as always they were very helpful. Suggested TPS settings but more important clutching. So I ordered that exact set-up.
I also built a tester and adjusted TPS to perfection. Went for a few rides and no change in the bog or det AT ALL.
A week later installed the SLP set-up and rode it and sure enough no bog, no det. Their map is perfect for their clutching. But,,, I like my sled to feel different. It was a little to zippy for me.

I like to clutch for 3100 to 3200 engagement and crawl up and over logs and into and out of creeks at 4000 to 4500. It is an 800 not a 600. It also has to flash up to peak rpms at any point from there. I like it to feel and pull like a CR500 in the trees. I ride a CR500 in 4th gear with a finger on the clutch in the trees.

Basically I created my own bog. It had nothing to do with TPS setting. It had everything to do with my map related to my clutching.
I do believe (after this season on the Poo) that the way the CFI fueling is set-up it is more critical to be spot on with the fuel required. I think it has everything to do with the distance of the injector to the combustion chamber and the time it takes to get there.
As I said above it was a very small lean spot at low throttle position in a small rpm window and with the buttons right there on the Boony box I was able to tune it out in the field pretty quickly.
 
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