Bruckner Posted September 22, 2018 Share Posted September 22, 2018 Hey guys, I've been having issues with my VFR for years, resulting in my not using the bike much. The engine is running rich with strong scent sticking to my riding clothes, I removed the airbox to check out the vacuum lines and found that the line going to cylinder #2 is badly damaged. Could this be causing a rich condition? I was initially pulling the box to check out the FPR, I thought maybe it was ruptured and was leaking fuel into the vacuum lines, but all seems fine on that end. Thoughts please! Link to comment Share on other sites More sharing options...
Urbanengineer Posted September 22, 2018 Share Posted September 22, 2018 Vacuum leak could definitely cause some issues. That one is a vacuum line for the flapper valve. I would check the rest of those out though... your boi is dusty! Link to comment Share on other sites More sharing options...
Bruckner Posted September 22, 2018 Author Share Posted September 22, 2018 OK I just replaced my plugs, all 4 old ones were only finger tight and most were not looking good, with at least 2 covered in fuel. Obviously new plugs are making the bike run a whole lot better (more healthy idle, no more interruption of power in low RPMs, great throttle control, etc), however the exhaust still smells rich. Aside from replacing the vacuum line shown above, I didn't do anything else to it, I'm afraid the fundamental issue that caused the plugs (which were admitedly more than 35,000 miles old!) to go bad is still present. Again, thoughts would be appreciated. The bike is stock aside from a K&N air filter and Leo Vince muffler, all else (including PAIR etc) is stock. Link to comment Share on other sites More sharing options...
GreginDenver Posted September 22, 2018 Share Posted September 22, 2018 You should read through this thread here on the VFRdiscussion forums, it's recent and still active and I think it might have some information in it that could help with your problem. https://www.vfrdiscussion.com/index.php?/forums/topic/88125-5th-gen-bad-mileagerich-running-opinions-on-what-to-check/&tab=comments#comment-1088633 Link to comment Share on other sites More sharing options...
Member Contributer Cogswell Posted September 22, 2018 Member Contributer Share Posted September 22, 2018 Judging by the gunk on the intake plenums above the throttle plates, I'd bet a paycheck that if the injectors were on a bench flow device that the flow would be poor, the spray pattern the same, and also probably not shutting off completely. Varnished fuel and debris in the injectors can cause the pintle not to seat properly so fuel keeps flowing in even though the ECU thinks it isn't. Also , a poor spray pattern doesn't atomize the fuel fully so some can go unburned. At the state of disassembly in the photo, it's super easy to remove the injectors - 4 small bolts removed, unplug and they lift right out. Professional cleaning is about $25 per at RC Engineering - can be sent US Mail. Fuel additives will never clean them to the extent that a full service can. Definitely worth it. Link to comment Share on other sites More sharing options...
Urbanengineer Posted September 22, 2018 Share Posted September 22, 2018 I swear you were paid to advertise for that guy here... looks like oil got on the plugs, which makes sense because you have a lot coming through your intake into the top of your throttle bodies if you see the burnt brown sections. For now, throw it back together and go ride and see if it’s still bad. Link to comment Share on other sites More sharing options...
Bruckner Posted September 22, 2018 Author Share Posted September 22, 2018 Thanks for quick and useful info guys! I did ride the bike and it runs better than I can ever remember, though it still smells rich leading me to believe the underlying problem remains. I will ride it for longer and then move to cleaning the injectors. I didn't want to mess around with the fuel rail but looks unavoidable... Link to comment Share on other sites More sharing options...
Bruckner Posted September 23, 2018 Author Share Posted September 23, 2018 Bad news, I took the bike out for a short ride, put some fresh gas into it, gave it the beans on the highway, then came the first red light and the motor died. Sometimes it'll hold an idle, most of the time it won't. The on/off throttle is now abrupt and exhaust smells terrible. All I did was fix a punctured vacuum line and replace spark plugs. The bike is now unridable. I'll try to adjust the idle but I'm pretty sure problems are more serious. Any thoughts (including sympathy) before I take it to Honda to fix? Link to comment Share on other sites More sharing options...
Urbanengineer Posted September 23, 2018 Share Posted September 23, 2018 Are you sure you aren’t riding my bike? The FI light comes on because of something related to fuel or air having an issue. Pull the code and start there. Link to comment Share on other sites More sharing options...
Bruckner Posted September 23, 2018 Author Share Posted September 23, 2018 Here are the codes: 1: MAP (electrical) 2: MAP (vacuum) 9: air temperature sensor These 3 would be due to my removing the airbox to inspect and fix the visible vacuum leak I had. I just removed the box again to check electrical and vacuum connections to MAP sensor and IAT sensor. I can see no problem unless I routed the vacuum lines incorrectly but I doubt it. I cleared the codes. If i l start it with some throttle to keep it from dying, code 2 flashes. I doubled checked connector and it looks fine. Problem must be the sensor itself or worse the wiring... Link to comment Share on other sites More sharing options...
Member Contributer Marvelicious Posted September 23, 2018 Member Contributer Share Posted September 23, 2018 Sounds to me like you have a major air leak happening now... I don't know why it would have suddenly gotten worse at a lights but the symptoms would make sense. Have you ever had the throttle bodies off? It almost seems like that assembly might not be seated fully. If you can get a stable idle, you could try the starting fluid leak detection trick... Fair warning: the internet forum safety police will tell you that this test is catastrophically dangerous and you will burn your bike down and probably die as well. Link to comment Share on other sites More sharing options...
Urbanengineer Posted September 23, 2018 Share Posted September 23, 2018 Probably just a loose hose mate. One of the five off the five way map splitter Link to comment Share on other sites More sharing options...
Bruckner Posted September 24, 2018 Author Share Posted September 24, 2018 I had to give up the bike to attend family duties, next time around I will inspect every single vacuum line. I have about 6' of replacement hose, I could be tempted to replace every single one. I suppose I should synch starter valves also. I never pulled the throttle body, only the airbox. Still not sure what caused my plugs to go so bad... Link to comment Share on other sites More sharing options...
Urbanengineer Posted September 24, 2018 Share Posted September 24, 2018 Time? Highly recommend plugging the pair system or air intake vent from the crankcase if possible as all that oil is over your TB intakes. Link to comment Share on other sites More sharing options...
Urbanengineer Posted September 24, 2018 Share Posted September 24, 2018 Don’t do what I did. Order some nice relxmdnt hose per OEM spec, or go silicone. https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F252995382038 Link to comment Share on other sites More sharing options...
Bruckner Posted September 24, 2018 Author Share Posted September 24, 2018 13 hours ago, Urbanengineer said: Time? Highly recommend plugging the pair system or air intake vent from the crankcase if possible as all that oil is over your TB intakes. Yes I actually did that yesterday, though only disconnected it, didn't yet block off the small pipe running to the left rear side of the airbox, will do that. I did notice that there was a bit of oil residue around the 2 rear velocity stacks. What does the other pipe going to the right rear side of airbox come from? Link to comment Share on other sites More sharing options...
Urbanengineer Posted September 24, 2018 Share Posted September 24, 2018 Directly top of cylinders 1 & 3 I believe. Link to comment Share on other sites More sharing options...
Member Contributer Grum Posted September 25, 2018 Member Contributer Share Posted September 25, 2018 21 hours ago, Bruckner said: What does the other pipe going to the right rear side of airbox come from? Crankcase ventilation hose/breather hose. Goes from the airbox to the top of the rear cylinders. Link to comment Share on other sites More sharing options...
Bruckner Posted September 25, 2018 Author Share Posted September 25, 2018 On 9/23/2018 at 8:58 PM, Urbanengineer said: Don’t do what I did. Order some nice relxmdnt hose per OEM spec, or go silicone. Just to be sure, you are advising against replacing vacuum hoses by the right size common automotive hoses? Why is that, if I may? Link to comment Share on other sites More sharing options...
Urbanengineer Posted September 26, 2018 Share Posted September 26, 2018 16 hours ago, Bruckner said: Just to be sure, you are advising against replacing vacuum hoses by the right size common automotive hoses? Why is that, if I may? I just went to the local auto parts store and bought some replacement hose and am not sure if it’s the source of my bikes idling issue. Link to comment Share on other sites More sharing options...
Bruckner Posted September 27, 2018 Author Share Posted September 27, 2018 Interesting. Did you replace all hoses? Perhaps the flow isn't matched from OEM Honda to automotive standard hoses? The replacement hose I got from NAPA sure fits the vacuum connections... Link to comment Share on other sites More sharing options...
Member Contributer VARIABLE9 Posted September 27, 2018 Member Contributer Share Posted September 27, 2018 It might fit, but may deform under vacuum (or pinch during install). Going to Napa or wherever is quick and easy, but the only way to ensure it operates as Honda designed it is to use Honda OEM parts. Link to comment Share on other sites More sharing options...
Member Contributer VFROZ Posted September 27, 2018 Member Contributer Share Posted September 27, 2018 It’s a vacuum hose. Its all it does, there is no flow. Any vacuum hose the right fit will do the job Link to comment Share on other sites More sharing options...
Member Contributer VARIABLE9 Posted September 27, 2018 Member Contributer Share Posted September 27, 2018 11 hours ago, VFROZ said: It’s a vacuum hose. Its all it does, there is no flow. Any vacuum hose the right fit will do the job There is air flow. That’s what it does. Link to comment Share on other sites More sharing options...
Bruckner Posted September 27, 2018 Author Share Posted September 27, 2018 I meant to say, mix and matching hoses could create differences in air flow restriction which could theoretically result in idle issues... Link to comment Share on other sites More sharing options...
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