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High fuel consumption


gropula

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16 hours ago, DannoXYZ said:

- gearing: taller gearing on Goldwing would lower engine RPMs at cruising speeds compared to VFR

 

- engine-tuning: VFR is tuned for high-RPM efficiency and max-power. GW tuned more for mid-range torque. At cruising speeds, engine-revs on GW would be closer to max-VE range in power-band (more efficient).

Very probable, GW rides mostly around 2500rpm whereas the VFR will be around 5k rpm.

 

15 hours ago, Grum said:

As per what Danno has mentioned, and also check your air filter for cleanliness,

Air filter is new, I check the filter again when I did the FPR and look clean.

 

15 hours ago, Grum said:

ensure the drive chain isn't over tight, and no brake drag!

will check.

On the other hand, and please forgive writing out of ignorance here... base on this link https://www.sidmartinbio.org/how-much-is-a-gallon-in-australia/  seems like Aussies use 4.545 liter per gallon instead of 3.875 as in US, that translates to 17% increment in fuel per gallon so 43 US MPG is around 50 AUS MPG, still shy of the 59MPG you saw on your 8th gen.

kinda off topic but the best mpg I have ever had on a bike was on the fz09, that thing did 52mpg (us gallon) with passenger, so sad that I totally hate the clutch noise on that thing and trade it for the GW, on the other hand my wife loves the passenger accommodations of the GW.

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6 hours ago, xlayn said:

On the other hand, and please forgive writing out of ignorance here... base on this link https://www.sidmartinbio.org/how-much-is-a-gallon-in-australia/  seems like Aussies use 4.545 liter per gallon instead of 3.875 as in US, that translates to 17% increment in fuel per gallon so 43 US MPG is around 50 AUS MPG, still shy of the 59MPG you saw on your 8th gen.

???

Gallons fortunately went out many years ago here!

My conversions of liters per 100k were to US mpg Not imperial mpg!

 

Metric is great - a liter is a liter in any country.

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  • 1 month later...

Ok, this is crazy now. Over the last 1200km my fuel consumption was freaking 9.5L/100km. What is going on with this bike? It was fine during the summer. Over the winter, since 11. September I drove 1200km and the fuel consumption skyrocketed. The fuel pressure  regulator has been replaced. The airbox is clean of fuel, checked when i replaced CCT's. I don't ride as hard in the winter, but the consumption went up from 7.2L to 9.5L/100km. 

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Maybe it is temperature-related. The ECU will run the injectors richer when the engine coolant temperature is low (as in a cold-start). How are the engine temperatures looking when running? A stuck-open thermostat can lead to colder-than usual running especially when the weather is cold i.e. winter in Croatia, but that should be obvious from the temperature read-out. The VFRs are intended to sit at a minimum 80-82C, anything less will be a stuck thermostat.

 

Another possibility is if the ECT sender or its wiring are damaged. The ECT has two circuits, one feeds to the dash display, the other to the ECU. 

 

A last thought is if the vacuum hose to the FPR is leaky, then the FPR won't see the vacuum from the inlet and will over-deliver. 

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Bike runs at 80-85C when warmed up, up to 100 in slow traffic an then the fan kicks in. Now in the winter it's around 77 while on the move. I've found that the vacuum hose to the MAP sensor was unplugged. Did a ride of 100km, used around 6L. Guess its fine now. Will monitor the tank for evaporation or leaks still.

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12 hours ago, gropula said:

I've found that the vacuum hose to the MAP sensor was unplugged. Did a ride of 100km, used around 6L. Guess its fine now. Will monitor the tank for evaporation or leaks still.

Vaccum hose off the MAP sensor, that's strange, why weren't you seeing your Fi light ON with a Diagnostic Trouble Code of 2?

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6 hours ago, Grum said:

Vaccum hose off the MAP sensor, that's strange, why weren't you seeing your Fi light ON with a Diagnostic Trouble Code of 2?

 

No codes because MAP sensor is not defective. It's not outputting 0-voltage or too-high voltage, which would trigger code. Its output is within normal operating range. Just that it's reporting WOT full-time to ECU. Which then injects more fuel than necessary.

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1 hour ago, DannoXYZ said:

 

No codes because MAP sensor is not defective. It's not outputting 0-voltage or too-high voltage, which would trigger code. Its output is within normal operating range.

No Sir.

DTC 2 is specifically for a MAP sensor loss of vacuum.

 

Example, when disconnecting the MAP sensor vacuum hose to do a Starter Valve Synch, DTC code 2 will be displayed.

 

There have been 6 and 8 gens that I'm aware of with a vacuum hose either broken or the hose has come off that force a DTC of 2.

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Ah, thanks for info. Looking back in thread, seems FI light not functional? He never mentioned even looking for codes. Very well could be some. Which would help make troubleshooting much simpler and quicker.

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5 hours ago, Grum said:

No Sir.

DTC 2 is specifically for a MAP sensor loss of vacuum.

 

Example, when disconnecting the MAP sensor vacuum hose to do a Starter Valve Synch, DTC code 2 will be displayed.

 

There have been 6 and 8 gens that I'm aware of with a vacuum hose either broken or the hose has come off that force a DTC of 2.

I can confim that when one is dumb enough to leave the hose disconnected from the MAP sensor, one gets a fault code. Ask me how I know...

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The FI light works, it was continually on when I switched on the bike with the airbox disassembled and one sensor on the bottom and one on the right disconnected. It never blinked before, while the vacuum hose was disconnected from the MAP sensor.

 

It could be that any of the requirements have not been met though.

6791FABC-4DF6-4C5F-80BC-B87E32F30C94.jpeg

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52 minutes ago, gropula said:

The FI light works, it was continually on when I switched on the bike with the airbox disassembled and one sensor on the bottom and one on the right disconnected. It never blinked before, while the vacuum hose was disconnected from the MAP sensor.

 

It could be that any of the requirements have not been met though.

6791FABC-4DF6-4C5F-80BC-B87E32F30C94.jpeg

If the ECM detects a fault while the sidestand is UP, the Fi light will be On continuously.

Yes, the Sidestand must be down before active fault codes are displayed.

The logic is that while riding you don't want a distracting flashing light grabbing your attention! The Fi light will be fully ON, codes will display when stationary with Sidestand Down.

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  • 4 weeks later...

An update! I replaced all vacuum lines and read all the codes. There were no active codes, but codes 2-8-9-12-13-14-15 were in memory. 2 is from disconnected vacuum hose to MAP, 8-9 from when I started the bike with the airbox off. 12-13-14-15 are fuel injector fault codes, don't know what that is about, but they are not active codes. Deleted all the codes, added some fuel injector cleaner to the tank and went for a ride. The ride by the odometer was 173km with 16.36L so that is again 9.5L/100km. Fairly agressive riding. No codes after the ride, not active nor memorized. Any thoughts?

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  • 1 month later...

Update... The bike was in official Honda service shop. One of the starter valves was damaged and it was replaced, then the starter valves were synchonized. The bike runs much better idle/low throttle/low RPM. The fuel consumption problem was not solved but it was narrowed down to the TP sensor. The mechanic concluded the TP sensor has been messed with since the white markings on the screws don't line up anymore. His recommendation was to replace the whole throttle body assembly with a new or used one since the TP sensor comes calibrated from factory and shouldn't be removed and/or replaced. This was prohibitively expensive so he said I should try and mess with it myself. Adjust it, replace it whatever. He won't do it since it's not per Honda's instructions.

 

I measured the voltages per instructions from the service manual.

 

Input voltage measured: Vi=5.03V

 

Should be (+\- 10% Tolerance):
Fully open
Vi*0.824=Vo = 4.14 (3.73 - 4.55)
Fully closed
Vi*0.1=Vc = 0.50 (0.45 - 0.55)

 

Measured: 
Vc = 4.65V fully closed
Vo = 0.55V fully open

 

So there is the problem. The voltages are the other way around. The voltage changes smoothly from 4.65 closed to 0.55 open. I presume the sensor was replaced by a similar one that works in the opposite direction. The text on the face of the sensor is not readable so I don't know what it actually fits. Any thoughts on what should I do?
 
 

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Any possibility to is wired backward? I've seen owners do some very strange things to their bikes, unemcumbered by knowledge. 

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3 hours ago, bmart said:

Any possibility to is wired backward? I've seen owners do some very strange things to their bikes, unemcumbered by knowledge. 

This, so much.  

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Yeah, measure voltages on other wires. Something got crossed.

 

Is there's also idle-switch on this model?

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6 hours ago, gropula said:

Here is what i did. I was baffled as well so I took a video so you can check if I'm doing something wrong. Tried running it with the sensor unplugged, it ran like a dog, wouldn't rev much at all. So I figured it can't run right with the readings backwards.

 

https://youtu.be/Ga-F9T1fyU8

Zdravo gropula.

Your voltages are Fine, BUT your measurement points are Not!!! 

Suspect there is nothing wrong with your TPS.

 

The reason your measurement is reversed is because you are measuring the TPS Output with respect to the 5v Vcc Yellow/Red wire B13.

Your Black meter lead needs to be on Signal Ground being the Green/Orange wire at B16. Red meter lead to the TPS output at A16 Light Green wire.

 

TPS wires at the ECM are....

B13 = Yellow/Red wire 5v Vcc. (Gray Connector)

B16 = Green/Orange wire Signal Ground. (Gray Connector)

A16 = Light Green wire TPS Output. (Black Connector).

Your TPS Output wire at A16 should be Light Green, not Light Blue as you mentioned in the video.

 

You haven't mentioned the type of fuel you use. Are you using either E5 or E10? Ethanol blended fuel along with agressive riding definetly won't equal good fuel economy.

 

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Thanks for the explanation. I'll try reading it the proper way today. I'm using what's available in Europe, Eurosuper 95RON BS E5. 95 octane, no sulfur content with up to 5% ethanol. On  short rides it's hard to get the same level of fuel back in the tank so I probably made a mistake stating that I got ~6L/100 in one of the previous posts. Later, other tanks were from 8.3-9.5L/100. Best I've got from a full tank was 6.9L/100, and that was riding open road with a buddy who is a beginner rider. 80% of the time I was cruising 6th gear 80km/h at around 4000RPM. Slow acceleration because he has a slower bike. VTEC noz even once in 200km. My gearing is 15/44 (-1/+1). Even when I'm riding with my girlfriend, which of course causes me to ride slower and more carefully I get ~8.2L/100. Sure, E5 gets you worse mileage, pillion as well, shorter gearing too. But riding steady at 80 km/h no pillion, at 4000 6th gear gets me 6.9L/100? Any time I open it up a bit it's 9+...

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Well, if it was my bike. I'd invest in getting the Injectors professionally cleaned and flow balanced, they are 20 years old.

Fit a new set spark plugs, and get rid of that K&N air filter, fitting the standard OEM. Would also try to use non Ethanol blended fuel if its available. See how fuel economy is after that.

Good luck.

 

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Ok I'll look into the injector cleaning. I tried running three tanks with injector cleaner. Didn't notice a change. What about fuel filter? Some people say changing it improved their fuel consumption. I don't think I can get non ethanol fuel here...

 

Update: Measured the voltage the right way round. 0.38V closed, 4.48 open. So closed was out of tolerance. Adjusted it so its 0.47 closed, 4.57 open. Now it's at the edge of tolerance on both sides. I hope this helps a bit, doesn't seem like a lot of adjustment was done, only 0.09V, but it might do something.

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