Adjust your TPS

[Eric GSX1400K3]

Checked and adjusted my TPS and STPS yesterday,  all readings at the sensor connectors. TPS at 1100 Ohm closed and 4217Ohm at wot.  As per spec.

STPS set to 799 Ohm closed. Went through the Airbox to hold the secondaries closed after removing the air filter. Found that if you actuate the secondaries via their common rod underneath the sensor, I.e. outside the airbox, you get the same result, so there is actually no need to remove the air filter. Pushing up on the rod from underneath closes the Secondaries, pulling down opens them.

All adjusted, restarted and found that the fast idle was also much better. Went for a 30minute ride and much improved low speed throttle response.  When hot, I adjusted the manual idle speed to sit just above 1000rpm (indicated). Happy so far.  Thanks for the valuable input here, much appreciated.

[BlueDragon]

Heads up with using this method.

Disclaimer - all bikes are different so this is just what I found with my 1400, others might be different.  I checked this several times over and using 2 different multi-meters.  To the point where the second one is brand new - purchased to make sure my first multi-meter was reading correctly.

When using the large plug to get the readings for the TPS and the Secondary TPS - your readings might well be slightly out and reading low when compared to getting the resistance readings directly from the plug connected to the sensors.

I checked this several times over as I installed a complete (spare) throttle body today.  I had previously checked the TPS and STPS directly at the sensor plug and got them exact.

Installed on the bike and then when through the whole throttle body balance process etc.

Then decided to check the readings again using the large plug - just to make sure everything was still OK after throttle body balance.

The readings were different from the large plug - I didn't think anything of it so I re-adjusted both sensors.  But then the bike started to run like a pig afterwards.

Taking everything apart again - I checked the resistance at the TPS sensor plug - it was wrong..  then compared to the large plug as mentioned at the start of this thread and it said it was right resistance.. - same issue with the STPS readings.

Again - I reset the resistance using the readings at the actual sensor plug - got both the TPS and STPS correct...  again. 

Started the bike and it was all smooth again.

So I suggest if you are going to use the large plug - I would just double check that it gives you the same readings as getting the resistance from the actual sensor plug.

For me.  TPS Sensor reading was 1.1 ohms resistance - but the large plug was reading 0.97 resistance

STPS sensor reading was .8 ohms (valves closed) but the large plug was reading 0.74

Not a big difference - but enough to make my bike run very rough and coughing at idle.

At least now, I know what the difference is and if I decide to use the large plug (being lazy) then I know what the readings need to be.  But I don't think it is all that difficult to use the plugs on the sensors.  Granted - a little more time to lift the tank and unplug the sensors.. but I'd rather get the right readings at the source.

[Monarchjock]

Bluedragon, if you look back at page 5 of this thread, Andre has  already made this point and I have given the difference in  readings I found on my setup.

[Andre]

Can't make this point often enough, especially for those who don't read the whole thread before posting (or have forgotten what they have read before). 

[BlueDragon]

Can't make this point often enough, especially for those who don't read the whole thread before posting (or have forgotten what they have read before). 

My bad - more I forgot what I read through with so much to read in this thread

[Will14]

Possibly dragging up an old thread again here but what would cause the TPS setting to need readjusting?

Just asking as I recently set both TPS & STPS to the recommended settings all was well, cold start was spot on & bike rode great. Over the last couple of weeks I have done the HP Fuel Filter bypass and also removed the Delkevic exhausts & refitted the standards, started the bike this evening & while she fired first time the cold start did not activate at all and bike was struggling to idle so knocked her off straight away, thought that was strange so I checked the TPS and it had gone up from 1100 ohms to 1180 ohms STPS was still spot on at 800 ohms, reset to 1100 ohms and although there was still a bit of heat in the bike the cold start seemed to kick in for a few seconds and the bike idled much smoother again - seems strange?

[Hooli]

The screws you balance the throttles with can move slightly due to vibration, heat can make the adjustment mechs between the throttle bodies change slightly due to differential expansion etc etc

[Persizi]

I did adjust my TP sensor today. Initially the reading was 1.3kohms idle and 4.45 fully open. I did it 1.15 idle and 4.3 open. I'm not sure how relevant is but the engine wasn't very hot. It's been about 2 hours after I stopped the engine. The weird thing is that even in the very end position on the sensor the readings are not 1.1kohms, it is about 1.12kohms.

[Monarchjock]

The weird thing is that even in the very end position on the sensor the readings are not 1.1kohms, it is about 1.12kohms.

If you have read through the whole thread Persizi you will see this is normal. Nothing to worry about.
If you take the TPS out it does adjust below 1.1k. Just seems daft that fitting it restricts the adjustment.

[grog]

Close enough Persizi, think i somehow filed mine out to get exact.

[Hooli]

It's the voltage returned to the ECU that matters really, not the resistance. But the resistance is much easier to check & gets it approximately right.

[Persizi]

Is someone knows what is the right size of the anti tamper screws? Because I hurt one and I want to change it.

[SteveW]

The check above is a basic extract from the workshop manual.

AlfaDave from the old forum suggested a couple of tweeks on this procedure.

1. Remove seat and LH side cover.
2. Disconnect large grey connector from under LH side cover.
3. Measure resistance between pins as shown on the top connector as per picture.
4. Resistance at closed throttle should be 1100 ohms or 1.1 Kohms, throttle fully open should be 4300 ohms or 4.3 Kohms.
5. Loosen the two anti tamper screws on the LH TPS and adjust to bring resistance into range (the bottom value is more important than the top value).
6. Set RPM to 1100 (manual) or 1200 (AlfaDave).

Throttle Position Sensor (TPS) gives an electrical representation of where the throttle is (1100 ohms closed), the TPS is a variable resistor which has  a wiper arm moving over a coil of resistive wire, if the TPS is not correct fuelling is adjusted by the electrical position which differs the real mechanical position of the throttle and causes numerous running problems.

Bine new to me was very Jerky on and off the throttle ( had to clutch her in on small roundabouts) so followed this one and it's not much much better ! However I can get 1100 ohms (was 1650) no bother but it's only 2600 on full throttle .  Bike runs well now .
Checked it with 2 meters and reading concurs

For me it's happy so I'm happy but anything going to get better still with new TPS sensor ?

[KiwiCol]

If she's now running smooth, leave it as is.  That'd be my suggestion.

[Hooli]

The upper reading is often wrong. It doesn't matter though, it's the voltage the ECU sees back from the sensor that matters & if it's running right then that can't be far off.

There are instructions in the workshop manual how to test that if you really want to waste your time over it.