FI light sputter high revs

Hello!

About the bike:
EURO 98’ VFR 800, bought second hand now has 100.000km, owned for 5 years, well maintained and used as a DD for the last 2 years clocking 60.000km since 2010 when I bought it.
Last valve adjustment 50.000km ago
OEM NGK sparkplugs, Oil and oil filter & air filter changed at 100.000km – changed every 7-8kkm.
Bike has a DFO installed which never has lead to any issues

There are two issues which I do not know if are related, otherwise bike runs smooth and strong:

1) FI Light:
I have the infamous FI light. It comes one as soon as I start riding the bike, even before it fully warms up. It started out about a year ago, first intermittently and progressively got worse: Once every 2/3 months, once every 3 or 4 weeks (and I daily drive it), and now daily.

The code when I put the side stand down is one long blink (10 = baro sensor).

2) Sputtering and hesitation
Between 6-7k in 6th gear while cruising, I get an almost unnoticeable hesitation, but it’s there. Also, between 10.5krpm and 12krpm WOT I get stuttering (feels like the bike is cutting out). The sputtering happend before I changed sparkplugs, and still happens now.

So far I have tested the battery voltage at Idle: 12.3V with headlights on, 12.8V without. Voltage is fairly steady (+/-0,2V) if bike is revved to 5k.

I don’t want start replacing sensors or spending €400 on new coils at the stealers and then it end up being a faulty R/R (it was changed 5 years ago for the OEM “upgraded” VFR version so it is a potential suspect)

Other than bad grounding somewhere:
- could it be coils? Is it worth it buying some second hand? Is there any way to check them efficiently?
- Could it be the fuel filter?
- Can a faulty R/R cause sputter/cut out at high rpm?

 

that is low dc output, should be mid 13's

 

Agreed - your Voltage is low. 12V batteris actually hold 2.1 to 2.2V per cell, so with 6 cells, the minimum a fully charged battery should read is 12.6. And 13.2 is better.

I can tell you that when my R/R failed (and that was the second one), I got FI codes for my speed sensor and Baro sensor. Once I replaced the R/R (again) and actually soldered the 3 yellow wires from the stator to the R/R, "miracuously" all my other FI codes went away.

Personally, I haven't heard of a Baro sensor actually failing on the bikes, although I'm sure its possible. But I would still suggest you start with the charging system, would could conceivably be leading to your stuttering issues.

Here's the link to "The Drill". See post #9.

http://vfrworld.com/forums/showthread.php/39277-How-to-fix-common-regulator-Stator-failures

 

Sorry I meant 13.3v with headlights on, 13.8v headlights off +/-0.2V when revving. Had done the test las week rechecked today (minor memory slip hehe).

Questions still up!

 

a bad baro sensor will cause incorrect injecter pulse width thus giving issues with fuel ratio. do you have any gear to check the output of the sensor like a dmm or scope?

 

yes...have a dmm..no scope tho

 

scope would be best, a good dmm will measure sqaure waves so you can test injector pulse width. does your manual give specks on baro output for dif elevations?

 

No manual, no idea where the baro sensor is or how it looks like... Maybe it's a bad conection to the baro, I've been trying to find a wiring diagram to no avail....

 

it will be a 3 wire unit on the airbox some where

 

sorry, it is located on frame rail by the fuel cut relay. should be last small black box on the right hand rear rail. it is further back then the battery postion. hope this helps

 

baro output is 2.6 volts at 3300 feet above sea lvl
it is 2.46 v at 4950 above sea lvl
it is 2.763 volts at 500 above sea lvl

hope that helps

 

as you can see it is a neg voltage coefficiant as altitude increases, so just extrapolate on the data i presented

 

i'm going to have to find a 5000ft mountain to take my dmm! Thanks man, appreciated! There are a couple of black relay-like looking cubes on the righthand side of the secondary frame. Any pictures of the baro sensor perhaps? I guess if it is completely busted it throws out a value for Sea level and bike should run fin at sea level, right? If this is the case and bearing in mind I live in Barcelona and commute daily @ sealevel I have my doubts it'll be the baro sensor...However I'll report back with findings!

 

may just be bad wire connections

 

if your ecm doesn't sea the baro sensor in spec, or at all then te ecm will use a set limp home mode to operate in. not going top be sea level. most like will be for 2000 ft above sea leval

 

Here's a link to a service manual that you can download; wiring diagram from memory is right at the back.

http://www.vfrdiscussion.com/forum/...onda-vfr-service-manual-optimized-bookmarked/

 

Can this be associated with the sputtering at high revs?

What would be your plan of action? (I think you detailed the procedure in @Zecareitex 's post?) Bare in mind I will probably have to explain it to my local indy given I'm low on tools and don't have soldering equipment at home (if anything needs to be regrounded and soldered).

Also, FI light isn't erratic in my case, it's pretty contstant daily now - 5 min into my ride. Doesn't fluctuate with turn signals or anything else...doesn't change if my headlights are on/off etc. Doesn't really seem to be infuenced by any other electrical device.

Btw, is/was the yellow 5th gen in the picture yours? I'd love to see a high def picture of it! Looks like a beautiful build!

 

+ 1 for the checking your earth block before you go any further.
Bad earths will cause FI light to do all sort of weird things, as well as making diagnostics very hard.
My 01 was having bad start, FI light coming on with blinkers, hesitating on throttle + more.
Once I fixed the earth block (soldered) it all went away.
I'm not saying that is your problem, but it needs to be checked before you get into more complicated stuff.