Over the past month or so I’ve noticed that every once and a while my bike will do something weird (2008 vfr800 w/5600 miles). Over the winter I put a Two Brothers Racing M2 slip on exhaust system (only NON-cosmetic mod I’ve made so far), and it seems like the problem has only occurred after I put that on. When I’m riding: At a constant speed and hit a bump (large enough to bounce my hand on the throttle). Or just finished speeding up (say just got to highway cruising speed from the on ramp), and back off the throttle to maintain speed. The bike will “hiccup”. Three times this morning the FI light came on for a second then turned off. Has anyone experienced this before? With the exception of the hiccup, the bike rides and runs fine, just wondering what’s going on. I have the PCV, AutoTune, and a K&N filter coming today. Any chance they will fix the issue, or make it worse?
With just a slip on, I'd be surprised if that was even the actual cause. With the FI light coming on, I'd try to see if it stored a code.
Search YouTube for vfr FI codes and you will find a video on how to jumper two electrical pins, then the FI light will blink codes. No special tools needed.
I'm not sure if the 6th Gen reads the same way as the 5th Gen. Under your seat (left side) there should be a service connecter. Its a little plug coming right out of the main wiring harness. Should be easily accessible. Its not hidden. You need to short this with a jumper wire (fancy word for a paper clip). Turn engine off. Keep the kill switch in the run position Use the paper clip to short the system, by sticking it into each plug on the service connector Turn the ignition switch to on (dont start the bike) If it stored a code, the FI light will blink "X" times. One long blink (i.e. 1.3 seconds) is considered 10 short blinks. So if you get one long, 3 short (o.5 seconds) that's the code for 13 blinks. It will repeat after a while. Codes can run as high as the twenties, so you could get long, long, short short short. If there is no data stored, the FI light will stay lit. Determine the number of blinks, if any, and let us know. Then we can tell you what the code is. Too many to try and list ahead of time.
Appears to be lean on partial or closed throttle. Take it to a Dynojet tuning center and have them throw it on the dyno. They should be able to recreate the issue and develop a fix. Many things in play with the autotune and other various sensors. A good Dynojet tuning center should be able to identify the AF issue and develop a setting in an afternoon. .
The installation of the autotune module, PCV, and a well developed custom map will fix your issue. A good Dynojet tuning center will put a smile on your face. You'll like the results. Enjoy. .
unless there's something else wrong. The bike shouldn't hickup. My suggestion is to run the codes before you park that thing on a dyno and end up paying a shop rate to fix some other issue that you could have remedied yourself.
I installed the PCV and AutoTune this weekend. I got anxous forgot to check to see if it stored any codes. I only rode it for a couple miles, but WOW! Soooo much better at low RPM's and so smooth through out the entire range. I'll post a better 'after install' later this week, and let you know if I find any codes.
