Hereís a straw to grasp at...
Have you replaced the clutch before or had the right engine cover off? Isnít there a crankshaft position sensor on the engine cover? If that is loose or if the connection is intermittent it would cause a problem.
Is the problem something you can hear or do you have to be there in person to feel something is wrong?
I'm sure your tired of spending money on parts but have you changed the oxygen sensor that's on the air box?
When mine went bad I don't remember it throwing a code, anyone else know a way to test the oxygen sensor?
My guess would be an Air Temp Sensor.
Guys........unload the parts cannon, it’s expensive and rarely leads to success.
More testing and troubleshooting............before replacing any parts.
As a reference there are tests for both the air temp sensor and the O2 sensor.
If the IAT ( intake air temp sensor) is unplug the computer uses a default value of 95*. So the engine will run without the sensor.
The O2 in failure mode......the ECU will disregard the sensor and the engine will run often with no notable problem. The primary job of the O2 sensor is keeeping the catalyst “happy”.
Last edited by showkey; 14th March 2019 at 17:49.
My experience with a bad 02 sensor on a Honda PGM-FI system (GL1800) is that it called no fault, engine felt normal, but it defaulted to open loop mode which made the engine run rich. The plugs were black and the gas mileage was horrible. But, the symptoms of the failure in my case did not mimic SargeantChuck’s. That’s not to say his problem may or may not be different than mine. It’s just a little data point, and probably not relevant to this thread.
This is the most recent list of things I have tried. I already replaced what I called the mass airflow sensor in the top of the air box.
1. Checked Oil Level
2. Replaced Spark Plugs
3. Replaced Air Filter
4. 3 X Tank of fuel with Seafoam
5. 1 X Tank of fuel with HEAT
6. Replaced Ignition Coils
7. Opened fuel cap while riding to test venting
8. Checked for loose ground wires.
9. Adjusted Valves
10. Removed and cleaned throttle body
11. Replaced fuel injectors and fuel rail
12. Inspected both air box gaskets
13. Conducted compression check @ 125PSI (Test was done wrong) Will retest this weekend
14. Sprayed starter fluid throughout entire engine area focusing on throttle body region
I have a busy weekend but I hope to check the compression a second time doing it the correct way and I will clean as many electrical connectors as I can access just for the hell of it.