SK5 high idle/malfunctioning STV valves after throttle cable adjustment??

[Barney626]

Originally Posted by glang

That's what I had on mine many moons ago (see my FI light thread) as the fault would come up after holding full throttle for a few seconds. Turned out STV position sensor needed adjusting to give the correct reading at full opening....

I did actually find your thread a while ago but that was while the bike wouldn't start properly haha.

Can you remember off the top of your head what the voltage/resistance readings are meant to be?

[glang]

You're best off downloading the manual. It's free somewhere and gives a good description of all the FI testing

[Barney626]

So thread revival.

Finally had some time to do some diagnostics using the service manual and found the following:

-STVA continuity correct
-STVA Resistance correct (9 ohms)
-STVS connector supply voltage correct (5V)
-STVS continuity (yellow-grnd) correct

-STVS resistances:
Closed=0.74 kohms (SPEC 0.58kohms)
Open = 4.38 kohms (SPEC 4.38kohms)

So I have an out of spec resistance at closed. I was hoping this was just going to be a case of adjusting the sensor but the open reading is correct so if I move the sensor to fix closed reading, it will move the open reading out of spec.

It seems the resistance range of the sensor is too small for some reason.
The strange thing is I only get an error at high speed where I would have thought the STVA would be fully open. I was expecting the incorrect reading to be in the open position as a result but this doesn't seem to be the case?

Is the extra 0.16kohms really enough to cause the error out at high speed?

I've been searching for a replacement STVS sensor but am struggling to find one listed for my model. I've found a few for curvy SV's but not sure if these are the same sensor?? can anyone confirm??

[Seeker]

Originally Posted by Barney626

So I have an out of spec resistance at closed. I was hoping this was just going to be a case of adjusting the sensor but the open reading is correct so if I move the sensor to fix closed reading, it will move the open reading out of spec.

Unless the potentiometer is max'd out at 4.38k, ie. after so many degrees of movement it reaches max value and then stays at that even if rotated further. I don't know if this is the case but I'd be tempted to adjust the closed position since you are/were complaining about a high idle.

[Barney626]

Originally Posted by Seeker

Unless the potentiometer is max'd out at 4.38k, ie. after so many degrees of movement it reaches max value and then stays at that even if rotated further. I don't know if this is the case but I'd be tempted to adjust the closed position since you are/were complaining about a high idle.

So out of desperation I loosened the sensor bolts and tapped it until the closed reading was 0.72 kohms just to see what happened.

Just been for a test ride and vastly exceeded the speed it was occuring at with no issues so it appears to be fixed.

I suspect what I did was knock the sensor while trying to put the airbox back in.

Will see whether the issue reappears in a few days but fingers crossed its all sorted.

[glang]

sounds like youve sorted it but not exactly as instructed in the manual. The sensor resistance values are only approximate and in the section on adjusting the STP sensor (section 5-29) it just says set it so that the voltage reading is more than 4.38volts at fully open.
In my case I suspect that when I held the throttle open for more than the set time (3 secs) if more than this voltage wasnt seen by the system the FI light came up. Believe the high idle is when a fault has been detected and the system is running in emergency mode...