FI Light and decelration stalling

I am a cable tech, not a mechanic and need some assistance. I have just installed the Two Brothers 2002-09 Honda VFR800Fi Dual V.A.L.E.™ Slip-On Exhaust System and a new K&N air filter on an 05 VFR800. Since doing this, the throttle response has not been smooth. As the bike decelerates it seems to be backfiring and stuttering, ocassionally it stalls when coming to a stop. The FI light comes on from time to time, but if I accelerate it lurches and then seems fine. Any help would be appreciated.

 

Make sure you did not disturb/relocate any wiring when doing your mods. Sounds like you may have and now are dealing with pinched wires, rub through, melt through, or just a plain ol screw up. Not meant to be insulting, we all have dumbass moments from time to time. Go back over what you did where you did it on the bike and have a good thorough looksie at all the wiring and farkles. Also, make sure the K&N is installed correctly and you're not sucking the filter oil directly into the intake, you didn't oil a new filter did ja??

 

+1. Really does not give alot to go on other than it was just tinkered with.Mods would not cause this problem, maybe something was disturbed? It happens to me from time to time and when I figure it out it is a big face slap.:doh: I have had a few superdeluxe dip shit whoppers over the years.

 

In addition to what Toe and Metallican are saying you may also have mapping issues with your new set-up. The sparking and popping that you're hearing is completely normal for a new 2bros. M2. It will break-in nicely after several hundred miles and the sound will get smoother and deeper. Although you will still get some occasional charachter sparking during decel, which sounds really good.

More to the point, it doesn't look like you've installed a power commander. The new exhaust and airfilter are more than likely causing some havic for your ECU. It can cause the bike to run rich or lean (usually rich) and may or may not be the source of your FI light. My understanding is that the ECU will eventually try to self correct, but it will never be as good a map as you had with stock pipes. For now it's trying to figure out fuel mapping for a stock exhaust and airfilter that are no longer installed. I would seriously consider buying a PCIII. It will allow you to maximize the performance of your new exhaust/airfilter and the bike in general. No more surging at off idle speeds, much smoother VTEC transition, and lightening quick throttle response are just a few of the many benefits, also eliminates the HP and torque drops at mid-tach. You can buy a PCIII on the cheap right now because Dynojet recently released the PCV. I've seen the PCIII for as low as $180 and it's really all you need for a 6th gen. Keep in mind that if you do purchase a PCIII, you will need 2 oxygen eliminators ($40) and there is no downloadable map for 2bros., so the only way to get the mapping 100% accurate and therefore gain the most benefit, is to put the bike on a dyno and get a custom fuel map. That will cost you roughly $250, but it's worth every single penny and will completely transform the way your bike runs and behaves.

Here is a link for the PCIII USB, you can find a PCIII without the USB for less with some searching.

http://www.kneedraggers.com/details/Dynojet_Power_Commander_III_USB_Honda_CBR600RR--19-DJ-3.html

 

If you got an FI light its code is stored in the the bikes computer. You can down the manual and see whats causing the problem. I would also check your idle speed in addition to whats been posted.

Action

 

Thanks to all for the insight. Hopefully tomorrow will be warmer and I can take a look at the wiring. I do not have a power commander installed and will look into getting one. Thanks again.

 

My bike behaved similarly to yours after I did my mods, and the PCIII install with a proper map solved everything, even added some unexpected power and torque. When I picked it up from the dyno tuners it was like getting a new and noticeably better bike.

Hope all goes well when you get the chance to inspect.