Bikesure_adrianflux

Running problem. TPS tickover value?

wasang

wasang

Registered
Joined
Oct 7, 2025
Messages
20
Location
Southampton
Bike
M900ie
Hi All. Can anyone point me in the right direction? (Ref, 2001 Monster M900ie "Dark".)
Bike was running fine until a few days ago when it started to cut out at tickover anything below 1000rpm.
Finally got it home and found that the TPS had come loose and the voltage reading at rest was around 110mV.
Set the TPS to 150mV when the LH butterfly was fully closed (had to release the cables, wind out the fast idle and RH stop screw
plus back off the LH stop screw)
According to the Bike Boy chart the 900Mie has an idle angle of 2.95 deg (462mV). I carried on the setup proceedure and balanced
the air flow with the air bypass screws wound fully shut. (Running on fast idle). After setting the air bypass screws out 1 turn I could not
maintain tickover no matter where they were set. (revs around 800rpm and again cuts out).
My questions are;
Is 2.95 deg the correct settings for the M900ie IAW59M ECU?
I have tried lots of different degrees as suggested but all lead to the same fault of cutting out below 1000rpm
The bike was running fine but does having Termignoni exhausts alter the idle position?
I have also noticed that the angles/voltages do not match the chart as the voltages seem a lot lower by about 50mV at any given angle (ref voltage stable at 5v)
Could this be due to an updated ECU map because of the exhausts?
Any ideas where I go from here would be much appreciated as I may be missing something obvious that I've failed to check,
Cheers
 
Iirc Idle speed should be 1100-1200 rpm usually. Not sure about the voltage needed. I'll have a look to see what info I have but I dont have this model. I assume its a non linear TPS?
 
Hi Darren. Thanks very much for your reply. Yes its a non linear TPS.
I was lucky enough to be able to connect the ECU TPS input to a voltage calibrator
that can inject accurate voltages at 1mV steps. I started at 150mV (displayed 0 deg) and increased
in 20mV steps to see what equivalent angles the ECU was displaying.
The results were the same as the TPS and were almost exactly 50mV less than the
stated value for a given degree. The formula that I was given is mV = (degrees x 105) + 150 which
all ECU's should calculate the same way unless it has been possibly remapped.
Could the ECU have been remapped for the exhaust system? If so, how do I calculate the idle value?
I may be overthinking the problem but so far I haven't found an idle point that seems to work.
Cheers
 
The Termi slip ons usually have a remapped ECU but I'm not sure if this should affect anything that your seeing. If you use diag sofware like JPdiag you can see the TPS angle and mV values on screen in real time.
 
152-150mv is correct on TPS its damn fiddly to get it exact and tighten the screws ,,I always set my S4 at 152 mv , tickover around 1100rpm is fine I have the same setup as M900ie Marelli IAW59M but i now have a DP performance ECU in instead of original with PC3 ,,,,
 
Don't know if M900ie is the same but for the TPS setup on 916, I just set the fully closed at 150mv then don't worry about mv or degrees numbers after that, rather just set the idle speed, as long as balanced and mixture OK then it runs perfectly.
 
Thanks for your replies. Much appreciated.
I will set the closed voltage to exactly 150mV and adjust the tickover on the LH stop screw to around 1100 rpm as suggested,
I'll get back to you as soon as I've tried it. Cheers
 
The angle set at rest on mine is 2.4 -2,6 degrees but it is a 4v so Idk as they are 50mm so different throttle body to the 2v ones iirc.
 
Thanks Darren. I'll try this setting and see what happens. I'm going to adjust the angle until I get a good idle at around 1000 rpm as you suggested.
Will report back
 
if its any help my S4 uses same TPS voltages 152mv and 4.62mv on DP ECU and standard ECU ,,,
 
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