CB1100 Idle speed instability problem

[peterbaron]

Doc,

I’ll look in the manual for the TPS. There is some info in there but I can’t remember detals. If nothing else, I know it lists min/max voltages.

Even though the TPS is not available separately, one knowledgeable member posted that is was the same a one off some car. He based this off the min/max voltages and actually tweeked his some. [Guys, DO NOT try this unless you are very experianced with this kind of thing. As noted before, there is NOTHING in the service manual for adjusting. Just big warnings to not touch it.]

I spent a couple hours trying to find that post and could not. He said it was a pretty common one, IIRC.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.
NOTHING wrong with popgun statement at all !!!!!!

Just want to add 2 cents...and I am NOT that mentioned knowledgeable member...

2013-14 HONDA-CB1100 :: TPS voltage & resistance test WITHOUT removing TPS
Test with digital multimeter (for advanced users)..
TPS (variable resistor) has 3 wires/pins: power supply(+), ground(-) and signal::

NEVER disconnect/reconnect TPS connector if IGN is ON, EVER
This is NOT a field fix to your problem - TPS test only
You do all these tests at your own risk/I assume no responsibility

IF you have a TPS problem = most likely you would have a DTC (history, pending or active, possible ELO/MIL ON).....or.....poor connection somewhere ...

WHEN ENGINE FULLY WARMED UP AND IDLING - WIGGLE/PRESS BLACK/3 PIN TPS CONNECTOR (near your L leg) and see if there is some RPM fluctuation.. = SIMPLE TEST FOR EVERYONE.

These advanced tests might be helpful::

TPS wiring::
black/yellow = power supply (+)
black/green = ground (-)
black/red = signal
This Honda diagram, I have, SUCS BIG TIME !!!!! = due to NO pin numbers

TEST 1
*IGN ON, Engine/stop switch OFF, backprobe ground and signal = about 0 Volts = OK when throttle is closed. NOTE:: I do not think it will be dead on 0/ZERO Volts, I think it will be slightly above..like 0.1 - 0.2 V
*TPS sensor VOLTAGE must smoothly/continuously increase/decrease when throttle is opening/closing respectively...so you MUST have smooth Voltage operation from about 0V (closed) to about 4.75 - 5.25 V at WOT = OK

TEST 2
*IGN OFF, Engine/stop switch OFF, DISCONNECT black TPS connector (3pins)
* TURN IGN ON, do NOT start (while TPS connector disconnected)
* Measure the voltage between black/yellow(+) and black/green(-) = MUST be within 4.75 - 5.25 V = OK

** Tell me what is your voltage between black/green(-) and black/red (signal), PLEASE = ? V **

TEST 3
*IGN OFF
* Disconnect black/3pin TPS connector
* Measure TPSensor side (NOT harness) resistance between black/red & black/green = within 0.5 - 1.5 kOhm = OK..
Manual does NOT tell me TPS resistance at WOT or/and between ground(-) and power supply(+)...but from my TPS experience would be above 1.5 kOhms

This entire TPS circuit consists of 4 connectors: TPS (black 3 pins), SUB black/10 pin, JOINT black/12 pin and ECM/ECU gray/33pin...and poor contact might be anywhere...would first start with TPS connector as per tests 1,2,3

Do NOT want to make complicated but this is how it works and how to test it
MAKE sure your throttle cable has some slack !!!
After disconnecting ANY connector:: check it, clean it, apply connector enhancer for better conductivity, please.

pb