High-G FJR Junkie!
Join Date: Jan 2013
Location: Millgrove, ON, CA
First, back to square one, verify no water in the fuel (Seafoam)...... then.... TPS. Yes it can test OK in DiAG, hot or cold, etc. Try this......
Copied from a friend...... Note, applies more specifically to Gen1/2. Gen3 has ECU controlled idle.
There is no need to guess about the TPS. Back-probe the TPS connector. Black DMM lead on the Black/Blue wire and the red DMM lead on the Yellow signal wire. At idle read .63 to .73 volts. Don't sweat a few milli-volts if it out of range. The way the TPS is attached to the main throttle body shaft the TPS idle voltage reading will change if you adjust the idle speed using the manual adjuster on the right side frame area. The ECU is mostly looking at throttle rate of change and span of throttle change instead of absolute voltage. If the TPS is bad in a narrow portion of the resistive track the ECU will see the sudden drop as a fast throttle change and will chop the FI off via the decel fuel cutoff and then when past the resistive track defect the ECU will see the sudden voltage rise like the rider is pinning the throttle wide open for a brief second and it's this rapid off/on that the ECU sees that makes the engine run so rough or outright stall.
Leave the meter back-probed to the TPS, Velcro/rubber band the meter to your handlebars and for a ride until it heats up. When the off idle misfire happens watch the meter. If it's the TPS, the voltage on the meter will notch down dramatically then come back up as you get the throttle beyond the (potentially) damaged spot inside the TPS. Steady, linear voltage = good TPS = look elsewhere.
The ECU provides +5 volt reference to most sensors and uses an isolated ground from the ECU so it is best to ground the meter to the Black/Blue wire and not chassis or battery ground.
Keep yer stick on the ice....
2014 FJR1300A - Root Beer