UPDATE: If you have read this topic from the start, then you know that this was really about trouble that my FJR was giving me at idle and very slow speeds; it felt fairly normal at speed...but idle and very low speed (under 5 mph) became the main issue. Bucking, hesitation...until it eventually got to where I had to keep the throttle open manually all the time when stopped (idle) and when coming to a stop. At one point, the engine warning light came on...but no error code. The light eventually went out (after about 10 minutes of riding). Light did not come back on. Continued riding the bike for another week after that, but the engine idle and slow speed riding got worse and worse...to where about 2 weeks ago [several weeks ago as of the posting of this update] I decided to stop using it as my regular daily commuter...and start trying to seriously troubleshoot it.
Well, after having spent about 30+ hours over the course of five consecutive weekends troubleshooting this (my only 'time off'), I was able to finally locate the problem: a small (as in
truly minuscule) crack/tear in a negative vacuum hose in the throttle body unit (between cylinder 3 and 4). That was it. The crack was located right where the hose was connected to the nipple (just where it 'clears' the nipple). As such, the tear/crack was about 1/4 inch from the tube's end...so all I had to do was cut the hose at that point and reattach it. Problem solved! Of course, a complete set of replacement hoses will take place once the order for those hoses arrives (which is on back order from Yamaha until the end of of next month (about 5 - 6 weeks from now). Fortunately, none of the other hoses are cracked (yet)...so I am keeping my fingers crossed that they'll be okay until the entire set of hoses arrives.
One take-away from this is the fact that the service manual and the various error codes that I encountered (which I attempted to troubleshoot using the service manual's 'suggestions') did nothing in terms of pointing me in the right direction. In particular, the
owner's manual states "
The [check engine] warning light comes on when an electrical circuit monitoring the engine is defective." It goes on to explain about using the self-diagnostic system (which I did, ad nauseam). It was precisely due to that specific text--"
electrical circuit monitoring the engine"--that i completely ignored first looking into something as simple/obvious as the possibility of a vacuum leak. IMO, having a
vacuum leak in no way equates to having
a defective electrical circuit!
For those of you with a schadenfreude 'bent', here are the things I did before spotting the little crack in the throttle hose (the vacuum leak):
- O2 sensor replaced (just because that seemed to be the most likely culprit)
- Spark plugs replaced
- Ignition coils checked (okay)
- Spark plug wires/caps checked (okay)
- Valve clearance check. Clearances were all within normal tolerances (okay)
- Timing chain tensioner (okay)
- Timing chain guides (okay)
- Throttle position sensor (okay)
- Coolant temperature sensor (okay)
- Air intake temperature sensor (okay)
- Cylinder Identification sensor (okay)
- Air intake pressure sensor (okay)
- Fuel pump/fuel pressure (okay)
- Fuel injectors actuating properly (okay)
- Fuel injectors 'leak down' check (okay
Especially enjoyable was having to re-replace the valve cover (cam housing cover) twice because of me not using enough gasket sealant the first time around (which created a small gap where oil leaked out of). Uggh! Of course, each time meant having to drain/refill the cooling system. Again~ uggh!
Well, I hoped you all enjoyed this pain I went through. But in all seriousness, I do want to again thank those of you who offered me advice...and especially the video and book from dcarver (without the info I obtained from those two sources, I most likely would have unnecessarily replaced my fuel pump). Thanks again all!