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2014 VFR800F/D. 42000 miles.

Starting about 4000 miles ago the bike started bogging down and then surging. If I'm maintaining throttle (like on the highway) it will start losing power even though I'm holding a constant position, then if I move the throttle its like it realizes where it's supposed to be and surges back to that position. It stopped doing it for about 3k miles after I had the full service done, but recently started doing it on a trip.

I thought bad gas so I ran the tank nearly empty (the condition got worse as the tank emptied), refilled it, and then it started doing it again 30 or so miles later.

I thought the Throttle Position Sensor might be going bad so I tapped into the system via my Power Commander 5. The PC shows that the throttle position (at least in my garage) works properly 0-100%.

 

The bogging/surging is kind of inconsistent so its hard to drop it off and say it does a thing when it doesn't do it all the time.  What am I missing?

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Hi lazyeye.

Sorry to here of your bike woes especially since it's a 2014 8gen. Nothing goes wrong with these bikes!!

 

Your symptoms sound like it may be a blocking/dirty fuel filter. Also adding to that might be a kinked breather hose which is so easy to do after raising and lowering the fuel tank. After a bit of riding and you open your filler cap, are you sensing any strong vacuum holding the cap down?

 

Assume you're not seeing the Fi Light coming ON or any flashing code? 

 

On the last service you had done do you suspect that tank may have been raised, possibly to replace the air filter or any other reason?

 

As per the photos attached. Have a very good look at where the Breather Hose small to large adaptor is located. If it's hidden further inwards that could mean a kinked hose. It needs to be very visible on the R/H side.

Good Luck hope this helps, keep us posted.

 

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The last maintenance was spark plugs, valve adjustment, air filter replacement... pretty much everything. The tank had to come off to do that work. I'll have a look and see if the breather hose is kinked. I don't detect any vacuum in the tank (its easy to open up just like usual) and there's no codes or warning lights showing up. I've heard that the charcoal filter can eventually get clogged up and cause running problems, is that real or is it an old biker story?

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8 hours ago, lazyeye said:

The last maintenance was spark plugs, valve adjustment, air filter replacement... pretty much everything. The tank had to come off to do that work. I'll have a look and see if the breather hose is kinked. I don't detect any vacuum in the tank (its easy to open up just like usual) and there's no codes or warning lights showing up. I've heard that the charcoal filter can eventually get clogged up and cause running problems, is that real or is it an old biker story?

Did this issue happen before Or after the last Service?

Does your bike have the Evap canister? Can't imagine how this system could cause your issues anyway. If the canister became blocked it could possibly effect the breathing of your tank.

Feel may you need to isolate the Fuel Filter, your issues are very much symptomatic of a dirty filter or fuel pressure issues. Maybe other members might have some ideas.

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The issue happened before I took it in for service and was independent of the last time I raised the tank. It was fine for about 3000 miles after the service, that's what really confuses me. My bike has the evap cannister, I've been too lazy to figure out how to properly eliminate it.

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1 hour ago, lazyeye said:

The issue happened before I took it in for service and was independent of the last time I raised the tank. It was fine for about 3000 miles after the service, that's what really confuses me. My bike has the evap cannister, I've been too lazy to figure out how to properly eliminate it.

You can simply unplug the electrical connector to the Evap Control Valve Solenoid and give your bike a good run, see how it goes.

Still thinking your Fuel Filter, may be an issue. You may have to try a fuel pressure and flow test as per the Service Manual.

Perhaps this is something you could have done where you have your bike serviced, they should also have good ideas of what to check based on your symptoms.

Is there anything strange going on with your Power Commander? How hard is it to disconnect, and have your bike running in a stock standard situation for trial?

 

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  • 2 weeks later...
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On 7/1/2020 at 1:41 PM, lazyeye said:

The issue happened before I took it in for service and was independent of the last time I raised the tank. It was fine for about 3000 miles after the service, that's what really confuses me. My bike has the evap cannister, I've been too lazy to figure out how to properly eliminate it.

Any update on your bike? I'm still thinking it's a Fuel filter or pump issue. Maybe with all the country tripping you've done you may have picked up some dirty fuel along the way.

Keep us posted.

Cheers.

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The shop has it. So I'm bikeless for the moment 😞 I'm probably going to borrow my mom's Vulcan 500 for the meantime.

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1 hour ago, lazyeye said:

The shop has it. So I'm bikeless for the moment 😞 I'm probably going to borrow my mom's Vulcan 500 for the meantime.

Hope the bike shop gets it sorted ASAP for you. Keep us posted with what they find.

Vulcan 500, that would be a very different beast to the VFR!! Go easy on Mom's bike!:fing02:

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Any ride beats a drive....  😎

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  • 2 weeks later...

I have a 2004 Vtec that is doing the same thing, reading through this tread I'll double check the breathers etc, however mine in factory, no power commander or map change.  So whatever it is its hard to diagnose.  I'm keen to see how you get on and what's found.

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1 hour ago, Damanisin said:

I have a 2004 Vtec that is doing the same thing, reading through this tread I'll double check the breathers etc, however mine in factory, no power commander or map change.  So whatever it is its hard to diagnose.  I'm keen to see how you get on and what's found.

While your VTEC shares a good amount of DNA with the 8th gen, it has its own issues with fueling and a very different ECU that's at least a decade behind the 8th gen's. The development of the VTEC happened in the late '90's when emissions regs were tightening and maybe the electronics were not as refined as today.  The AFR's were tuned to be very lean, to the point where it could be too lean under certain conditions.  You can search through the forums for remedies owners have instituted over the years.  In my case I used a Power Commander to adjust the fueling, and with an injector cleaning dispensed with those issues. These days I'd probably get a Rapid Bike  module vs a P.C. and let it tune itself to a bit richer AFR and see what you get.  If you still have the PAIR system be sure the valves are clean and there are no leaks in the system. 

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2 hours ago, Damanisin said:

I have a 2004 Vtec that is doing the same thing, reading through this tread I'll double check the breathers etc, however mine in factory, no power commander or map change.  So whatever it is its hard to diagnose.  I'm keen to see how you get on and what's found.

Agree with what Cogswell has suggested. But first check/replace your Fuel Filter, your bike is now 16 years old, hesitation, slight loss of power or surging at constant highway speeds is a good sign of a Fuel Filter issue.

 

Could you have recently picked up a bad batch of fuel? Condensation in your tank? Keep away from Ethanol blended Fuel if you can avoid it.

 

The 6gen does not have the same tank breather issue as the 8gen, so don't worry about the breather.

Cheers.

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  • 4 months later...
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I have my bike back. After four months of waiting for parts (warehouses show parts in stock that aren't and by the time they figure it out its been a month....) I had my mechanic use a rebuild kit on the fuel pump. Its running good now. Now I need to snowbird south and ride around the desert for the next few months!

The fuel filter was pretty well clogged. My reasoning is that had something to do with the pump failing.

 

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Good to know you're finally up and running again. Given the age of your bike, the filter blockage could have only come from one or two very bad batches of fuel, possibly from some outback town you've visited. Reassuring to know you have a new pump to go with it. Enjoy your southern travels. Safe riding.

Cheers.

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17 hours ago, Grum said:

Good to know you're finally up and running again. Given the age of your bike, the filter blockage could have only come from one or two very bad batches of fuel, possibly from some outback town you've visited. Reassuring to know you have a new pump to go with it. Enjoy your southern travels. Safe riding.

Cheers.

I've visited some gas stations that didn't look like they were open. Just run down shacks in the middle of nowhere with a pump out front. Finding out that the name brand gas station you'd planned to fill at closed a year ago and having to fill at Uncle Peet's Gas and Meth emporium is why we call it an adventure.

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  • 5 months later...
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I recently followed this thread with considerable interest, since I have a newly acquired 6th-gen (2002) RC46 VFR with what seems to be an identical issue! I'll be running the bike in 3rd or 4th gear (I'm a very 'born to be mild' rider) with the tach indicating between 5K and 5.5 or so, and maintaining a steady throttle position, when the power starts to fall off somewhat. To correct that, I have usually applied just a SLIGHT bit of throttle, at which point the bike surges annoyingly. I like to ride at a steady rate and 5K, so having this 'drop-off and surge' thing is a rather big frustration! I have no real indication as to when the bike had its last 'serious' service', but with 32,687 miles on the clock, it's probably time to take her in and have her get the recommended work done for 32K. HOWEVER, meanwhile this problem is really causing me a load of annoyance.

 

I noted the suggestions about possible fuel issue, as well as the caveat about checking/replacing the fuel filter and making sure the fuel pump is operating properly, so I'll definitely mention those suggested 'remedies' to my mechanic, but if that doesn't resolve things chop-chop, it's back to square one again! The bike has NO Power Commander, BTW and also has a stock exhaust system and fuel system. Since LAZYEYE's bike is 8th-gen (2014), it's interesting that BOTH my 6th-gen and his 8th-gen seem to have an idedntical affliction.

 

All of this simply makes me wish sincerely that I hadn't so rashly sold my 2000 5th-gen Viffer, which was a beautiful machine, stable throughout the power band in terms of providing smooth response, and never gave me a single issue. Amusingly, I'm sure a 'mild rider' that I haven't even encountered the EVIL VTEC spirit, yet...unless this issue is somehow connected to the extra complications of that system. [My machine is a California model (it even came with a small 'Saint AOC be our Protector!' medallion...yeah, li'dat!)] 😝

 

 

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Kalikiano - see my previous response to you.  Normal behavior...but defeatable.  Try the key switch method before jumping to fuel pumps, etc.  

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8 hours ago, Kalikiano said:

I recently followed this thread with considerable interest, since I have a newly acquired 6th-gen (2002) RC46 VFR with what seems to be an identical issue! I'll be running the bike in 3rd or 4th gear (I'm a very 'born to be mild' rider) with the tach indicating between 5K and 5.5 or so, and maintaining a steady throttle position, when the power starts to fall off somewhat. To correct that, I have usually applied just a SLIGHT bit of throttle, at which point the bike surges annoyingly. I like to ride at a steady rate and 5K, so having this 'drop-off and surge' thing is a rather big frustration! I have no real indication as to when the bike had its last 'serious' service', but with 32,687 miles on the clock, it's probably time to take her in and have her get the recommended work done for 32K. HOWEVER, meanwhile this problem is really causing me a load of annoyance.

Hi Kalikiano.

Strongly suggest before going down the path of fitting a PC or the RB that you check the fuel filter and pump etc.

 

It's common with any bike to cause the issues you have by poor fuel delivery. I'm not saying conclusively that this is the cause in your situation, but it certainly needs checking. Note, your bikes fuel filter is almost 20 years old!

 

My three previous 6gens and current 8gen have never experienced your issue. A friends 1998 5gen which I've ridden recently is stock standard and runs just fine, no fueling issues at all. Bikes don't come from the factory with your issue!

 

There's no doubt that people have good success with fitting a PC for added performance tuning..... BUT you don't want to be fitting one and trying to mask out a fault which may be as simple as a bad batch of fuel, blocked fuel filter,  faulty spark plugs, or dirty injectors etc.

 

Shipfixer's method of trying open loop mode is a good trick to try that could help to isolate your issue. If you still have problems in this mode then the fuel filter and/or pump need looking at.

 

Don't be too concerned about the loss of your fabulous 5gen. A well running 6gen will put a smile on your face, even with VTEC and without the gear driven cams!

 

Just a thought!! As always YMMV.

 

Good luck, let's know how you get on.:fing02:

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these bikes ran perfectly fine when leaving showroom floor with no stumbles anywhere. With age, wear and tear, you've now got EFI system that's no longer factory-fresh clean and with OEM spec parts. Proper troubleshooting and tune-up procedure is to measure each component and sensors. Then compare to numbers in manual to determine where problem lies.

 

It may be multiple components; some needing cleaning, some may require adjustment, and some replacements in rare cases.  There's even test of fuel-system flow by measuring volume pumped in X-seconds. Idea is to get bike cleaned and adjusted back to factory showroom condition. Then it'll run like brand-new.

 

This is similar to old desperate approach with dirty and clogged carbs. Gee, I've got stumbles and hesitations. Must be low fuel flow. Let's just install giant jets, that'll fix it! Low and behold, bike runs better with humongous jets, I was right!

 

Except that bike only runs 60-80% as well as brand-new bike. Improvement was due to installing clean components, not in up-sizing them. And ignoring scrubbing of hidden petrol passages and bleed-holes sacrificed 20% of restored performance you could've had.

 

In this case, installing PC may mask clogged injectors and fuel-filter issues in mid-range, but will endanger your engine under high-loads where you'll run lean for sure and risk blown headgaskets and holes in pistons!

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Disagree, the annoying closed loop behavior has been present in my bike since I took it off the showroom floor in 2003.  The early days of VFRD, Vfrw, Bay Area VFR, etc are full of stories of all of us trying to break this code and make it feel like a cable operated carburetor, comparing it to cat-less F4i's and 5th gens, etc.

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1 hour ago, ShipFixer said:

Disagree, the annoying closed loop behavior has been present in my bike since I took it off the showroom floor in 2003.  The early days of VFRD, Vfrw, Bay Area VFR, etc are full of stories of all of us trying to break this code and make it feel like a cable operated carburetor, comparing it to cat-less F4i's and 5th gens, etc.

Interesting ShipFixer, I wonder if these issues you talk of are peculiar to the USA version. 

The riding group I was heavily involed with for 15 years or so had VFR owners of 6gens, there were at least 6 or 7 6gen owners that purchased their bikes from new including myself, I had fairly close contact with them, appart from the odd cct, stator/RR and a bad tank of fuel, I cannot recall anyone complaining of what your describing. 

Frankly, if I'd purchased a new bike with issues like this I think I'd be demanding a fix or refund!

Like I mentioned my mates 5gen had none of the issues either. Is it possible that Honda resolved the issue with the 6gen from models post 2003. My first 6gen was a 2004 and had no problems.

It will be very interesting to know the proper cause of Kalikiano's problem.

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I think some people either don't notice/care or have forgotten.  In CA I was on long highway trips where it was obvious and not a transient thing.  Everyone who came from a carbureted bike hated it.  I completely forgot about it until I repurchased my bike and felt it again.  

 

I also bought my bike after a chief engineer tour on a little diesel ship with a...questionable control system...and in the middle of MechE grad school for a bunch of related stuff including linear controls so it drove me pretty bonkers right away that this was the best Honda could do.  If you really, really want to see it, get a stock 6th gen that's had starter sync and everything else done lately to set it to baseline, and put a throttle rocker or similar device on it.  The long leverage makes it even more obvious and annoying.  I sometimes had a choice between using the rocker to save my hands and getting absurdly annoyed with the ECU.  

 

My friend's 2001 did not do it, but my 2002 always did it, as did everyone else's.  In the last few months though a *lot* of things make much more sense than they did in 2003 though.  I am pretty glad I didn't try a PC3 but very satisfied with the technical approach to the RB.  It makes sense to dispense with the Honda inputs as much as possible.

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Should also add the forum has crashed a few times since then.  But the original owners were obsessed with two common goals...how to smooth out VTEC (mine has never been bad, especially after starter valve syncs and such) and how to correct this closed loop behavior.

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Appreciate your comments Shipfixer regards potential design flaws with Honda closed loop for the early 6gen.

 

I guess what I'm really getting at is that there is heavy evidence (and this particular thread is a classic example) that a very common (but not always) cause for a bike to start surging and bogging is fuel delivery and this is what should be assessed first before jumping to a PC or RB potentially masking a fundamental root cause of the problem. YMMV.

Cheers.

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