Author Topic: TPS adjustment instructions here(Big improvement!!) (Read 65348 times)

rider123 · « **on:** November 01, 2005, 08:23:20 PM »

Here are some instructions(from maximum suzuki) to test the TPS on Bandit 1200's. It gives you more throttle response and better gas milage. Allegedally they are usually set wrong from the factory so I'm going to check mine tomorrow. HEre are the instructions and I've made a bad ascii diagram to help you guys out, sorry no pics.

Pre Adjustment:
Measure Ohm 1, throttle closed, range should be between 3.5K - 6.5K if sensor is OK. Note your measurement on paper

Measure Ohm 2, throttle fully open, range should be between 2.66K - 4.94K if sensor is OK.

Adjustment:
Take the measurement from Ohm 1 on the paper. Mine was 4700 Ohms.
Now take 76% of this number which for me is 3720 Ohms.

Set your throttle to wide open position. I used a bungy cord wrapped around the
throttle to hold it wide open and take the measurement if you have no helper.

Now take the measurement of Ohm 2. Mine was off, so with the throttle fully
open, I adjusted the TPS to 3720. It's very sensitive to movement so small movements are required. Snug the screws.

Re check and verify:
Set the throttle to closed, take measurement of Ohm 1 again. Mine stayed
at 4700 Ohms. (If yours moved, write down this number. This new number will be used as Ohm 1 of which you will take 76%.)Set throttle fully open and measure Ohm 2. Mine stayed at 3720 so I was done, tighten the screws.

You may have to go back to the adjustment procedure to fine tune if you find that Ohm 1 changed from the initial setting. In my case IF the 4700 changed as part of the adjustment procedure, i'd have to measure Ohm 1, take 76% of this, and go through the adjustment procedure again.

Remember: Ohm 1 is ALWAYS measured with throttle closed
Ohm 2 is ALWAYS measured with throttle fully open.

Here is my bad ascii diagram:

_ _ ___
| - - - |
----------- <- this edge is on the outside of the bike
1 2 3
\.... /
Ohm1 -------------------------- 3.5K to 6.5K on bandit 1200(Measure with throttle closed)

_ _ ___
| - - - |
----------- <- this edge is on the outside of the bike
1 2 3
....I /
..Ohm2 ------------------------- %76 of R1 which is 2.66 to 4.94k(Measure with throttle open)

I hope this clears it up I'll confirm this all tomorrow on my bike but this is from the Haynes manual and confirmed by the other posters.

Sorry for bad ascii.

But did it help???

Here is the answer, his next post

I'm psyched! Mileage went from low 40's to high 40's from nothing more than the TPS adjustment. Previous to this, no matter how kindly I rode the bike it never did better than low 40's to a max of 44. With 175 miles of highway, backroads with John J. Saturday in Western MA. + another 25 miles of slow back roads + a hard blast down a 1/2 mile stretch, I got 47. So there is no doubt that the TPS position
affects the timing at low throttle openings.

Another guy had a stage 2 kit and his response had a huge lag time. He set up his TPS and it was wheelie city!! WHile it doesn't add any more power it does help with driveability and milage.

ray nielsen · « **Reply #1 on:** November 01, 2005, 09:25:39 PM »

The TPS setting provides feedback to the ignition module as to throttle opening. The neutral switch tells the ignition module what gear you're in and selects the "optimum" advance curve.

The TPS receives +5 volts and ground from the ignition module and it's applied across a 5K ohm potentiometer. The voltge at the arm of the potentiometer varies the voltage being fed back to the ignition module to "tell" it where the throttle is at any given moment. This sets the point on the selected advance curve where you're operating, and hopefully represents optimum timing for the gear you're in and the position of the throttle you've applied.

The neutral switch has four wires coming from it and the switch supplies a ground to two places, the neutral lamp when in neutral and then one of three different wires going to the ignition module when a gear is selected.

One wire is grounded in 1st gear, another in 2nd gear and a third in 3rd. gear. None of the three wires are grounded in 4th or 5th gear, effectively selecting (defaulting to) the same advance curve for both of the higher gears.

It makes sense that adjustment of the TPS would affect gas mileage and running smoothness to some degree.

Hope that helps.

mike · « **Reply #2 on:** November 01, 2005, 10:24:30 PM »

Here's the page from the Suz manual for reference and pics...

rider123 · « **Reply #3 on:** November 02, 2005, 06:45:47 AM »

Thanks guys, mine is out from the factory!! You'd think they would set it correctly. Well I'll reset it tomorrow to the proper specs and see if it fixes a teeny weeny bit of stumble at low RPM's. If I'm guessing right the TPS thinks I have more throttle open than I do. I still don't have the manual!!! For example on Mine:

I set the voltmeter wrong so I didn't get a super accurate reading (only good to tenths)

Throttle closed Ohm1 reading - 5.1k
Wide open Ohm2 reading - 4.2k <-------------should be 3.9K

Which way do you turn to increase or decrease it? CLockwise increase? Counter clockwise decrease?

So if I get you correctly ray if you disconnected the TPS it would default to the advance curve of 4th and 5th? I guess it's enough to get you home.

rider123 · « **Reply #4 on:** November 02, 2005, 06:22:19 PM »

So I adjusted the TPS as it was out of wack straight from the factory. Wow! What an improvement! The misfire/stumble issue is basically gone or so low I can't even discern it. It's still lean and slightly flat but smooth no skips/drops in power. Throttle response at low rpm has dramatically improved. Today, I got mad at this silly woman on a cell phone trying to learn how to drive or something, total idiot. So I wacked it 1/3 throttle open around 2K and the wheel went up off the deck a couple of inches and zooom!! I was off! It never did that before. Now I'm scared, but in a good way

Vibrations have seemed to be improved slightly as well, I only say slightly because my bike needs a carb sync badly. I don't think the dealer did squat to my bike. THey probably filled it with oil made sure it wasn't going to fly apart and said "good luck". Arrgggh. Fine I'll just take the servicing elsewhere. You would have thought they would have at least check the TPS which takes a whole 2 minutes to set properly. As far as gas milage goes I don't know yet as I just filled up today and changed to regular gas. It seems smoother and a little snappier at small throttle imputs but I'd need a full tank and an odometer reading and what not to say for sure.

While I can't say there is more power, it is definatly snappier, especially in traffic when you're mostly in the low to mid range crusing and you need a burst of speed to get you past a car that's driving slow and sh!tty. I think this TPS setting would probably make the most difference if you had a stage 1 or 2 with a proper pipe. If you can get some improvments with the EPA's propriatary "Lumpy tune" carbs, imagine with proper jetting and pipes!! Try setting your TPS up even for the supposed gas milage gains you have nothing to lose. I have a crappy Ohm meter good to only one decimal place and I got some improvement. It would be nice to have a super fancy 3 decimal place one to really tune it.

Here are the numbers I got just so you can compare:

Ohm1 5.1k <-------Two outer posts with throttle closed

Ohm2 4.2k <-------Two right hand most post with throttle wide open

Moved the TPS sensor CLOCKWISE to adjust it to 3.9k which is 76% of Ohm1.

I'll post the rest of my findings later have to fix computers now 5:31pm

K back. It's almost more annoying now because all it needs is a half turn or so on the pilot screws and a carb sync and I'm done. I highly recomend you check yours it's fast and easy. Tomorrow it's going up to 17 degrees. I'll see if the bike runs better when the air is a little warmer and it's richer. Damn plugs! I'll get them taken out by the dealer at 1000kms, he'll need to do it to fix it anyway.

Thanks for all your help guys, you rock!

scooter69 · « **Reply #5 on:** March 29, 2007, 01:33:09 PM »

Here's a good one for you guys...what do you do if the TPS doesn't show anything on the Digital Reader?

I tried using both digital and Analog, neither moved at all.

I took the TPS off, and there still is resistance in the spring inside.

Any ideas?? Is this one screwed??

salty · « **Reply #6 on:** March 30, 2007, 01:36:41 PM »

just checked mine too,no reading until you put the meter to megohms, then you get a reading in the very high range, spoke to my dealer (i have only had the bike a month so its still under warranty)He tried to fob me off at first but once he new i was quoting from the manual he admited it's stuffed, and has booked the bike in to be done. so had i not read it on here ond gone to fiddle, i proberbly wouldn't have known, be interesting to see how she goes afterwards because it was quite nimble before (mind i did move up from an old xs650 twin with all of about 50hp on a good day). they cant do it for a week, would it be beter to disconect it all together ? (tick over was a little lumpy but not too bad,it had a full service with valves and ballance prior to purchase)Any thoughts?

salty · « **Reply #7 on:** April 06, 2007, 01:14:17 PM »

Garage confirmed tps is goosed,new one order, been told to disconect it in the mean time, it does seem marginaly better this way, i'll let you now how it compares to the proper setup as i have yet to ride it with a working TPS. Had it not been for the forum, i would never have known!

Rocketjock · « **Reply #8 on:** April 08, 2007, 01:04:30 AM »

When I did the math, I found my acceptable but out. Made the change and really couldn't tell you if it made any diff or not. No lessening of decel pop. Gonna have to start using my brakes more and gearing down less to stop, that's all. Old habits die hard.

longislandbandit99 · « **Reply #9 on:** April 13, 2007, 07:52:30 PM »

Does my 2002 B12 have a TPS?

Rocketjock · « **Reply #10 on:** April 13, 2007, 08:53:59 PM »

Outside right side carb. You can probably see it better than us.

Red01 · « **Reply #11 on:** April 13, 2007, 10:56:11 PM »

You can see the TPS unit in the photo of the #4 carb in service manual excerpt in mike's post above.

mademiriam · « **Reply #12 on:** April 14, 2007, 12:39:50 AM »

It's so easy to see you're probably looking right at it but thinking it has to be more complex...I'm going to do this right now, since the bike hasn't run yet I guess I won't be able to do a comparison, but it doesn't hurt to get it right

salty · « **Reply #13 on:** April 14, 2007, 10:05:45 AM »

Garage fitted new tps yesterday, the bike feels completly different,much smoother at medium throttle settings and far more responsive from the lights,No huge power boost, just an all round more pleasent drive.My TPS was not working from day one (second hand bike) and i rode it disconected on the advice of the garage until the new one was fitted, my findings are that disconecting it acheives nothing other than poor fuel consumption and a flat spot (Bike is standard other that a scorpion can).
Salty

longislandbandit99 · « **Reply #14 on:** April 15, 2007, 02:43:17 AM »

Wow I never saw a manual with directions like that. Whatever I downloaded is only a parts manual or something. Is that description what I've been told is Jinglish?