Member Contributer PorradaVFR Posted February 18, 2014 Member Contributer Share Posted February 18, 2014 My 2004 is running fine and is all factory (no exhaust system changes, factory air filter, everything as it should be) yet with mostly commuting miles I'm getting ~30mpg which is lower than I used to get on my former 2004. I was having the flat spot issue and for a time had O2 eliminators on the sensors but didn't find any dramatic improvement so I removed them. I also ran some Seafoam through the system a few months ago over a few tanks of gas (the PO had her sitting for a few years) in case it was some crud buildup causing the flat spot but again there was no miraculous change. I'm not anxious to get into a quest for some gremlin, but I would like to be seeing closer to 40mpg. Any ideas? Throttle body synch worth trying? Link to comment Share on other sites More sharing options...
sudo Posted February 18, 2014 Share Posted February 18, 2014 How's your engine temperature? Maybe the thermostat is stuck open. Link to comment Share on other sites More sharing options...
Member Contributer Duc2V4 Posted February 18, 2014 Member Contributer Share Posted February 18, 2014 Maybe check out this thread... http://www.vfrdiscussion.com/forum/index.php/topic/76673-poor-fuel-economy-2009-vfr-800/ Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted February 18, 2014 Author Member Contributer Share Posted February 18, 2014 How's your engine temperature? Maybe the thermostat is stuck open. I don't believe so...the fan cycles on/off normally. Is that a valid sign that it's working ok? Maybe check out this thread... http://www.vfrdiscussion.com/forum/index.php/topic/76673-poor-fuel-economy-2009-vfr-800/ Just gave it a read through...and now I'm indeed wondering about the thermostat. What's the best way to check it? Link to comment Share on other sites More sharing options...
Member Contributer FM1 Posted February 18, 2014 Member Contributer Share Posted February 18, 2014 The bike should get to 170F within the first 2-3 miles of a ride and then maintain temperature. It can be easily diagnosed when its chilly outside. When I had this issue, I was running at 158F to 160F after 30 min of riding when ambient temperature was 60F. Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted February 18, 2014 Author Member Contributer Share Posted February 18, 2014 The bike should get to 170F within the first 2-3 miles of a ride and then maintain temperature. It can be easily diagnosed when its chilly outside. When I had this issue, I was running at 158F to 160F after 30 min of riding when ambient temperature was 60F. Well I rode into work today and it's relatively quiet....maybe I can sneak out a little early to check the bike out. I did notice this morning gassing up that the fan was coming on as I would expect (~215F) and I did not notice it running particularly cool....but I was not looking for it. Thanks for the input. Link to comment Share on other sites More sharing options...
Member Contributer FM1 Posted February 18, 2014 Member Contributer Share Posted February 18, 2014 I would also suggest testing it out when its less than 60F and NOT in stop and go traffic. I had this issue for a year but didn't notice it until this winter..Fresno is so hot most of the year that you dont notice a stuck open thermostat. Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted February 19, 2014 Author Member Contributer Share Posted February 19, 2014 Ok, so...~45 mile jaunt in the hills on the "way home" today to try to suss this out. In light traffic/stoplights (~60F, high temp seen was ~190-200F) In the hills (~50-55F, high temp seen was in ~170F) Highway run on the way home (~55-60F, mid-170s to mid-180s as ambient temp rose) Based on FM1's comments above I think I may be ok in regards to the thermostat working correctly - agreed? Link to comment Share on other sites More sharing options...
Member Contributer FM1 Posted February 19, 2014 Member Contributer Share Posted February 19, 2014 Your thermostat seems to be fine. Before you go through starter valve sync I would suggest checking your idle speed. You have to check it once you bike is warmed up --around 170F. Adjust it low enough so the bike doesnt stall at idle. Mine is set at around 900-1000 rpm. For syncing you will need a multi meter (since you dont have a PC) with rpm and manometer.....if you dont have these, you are looking at an investment 150-200 bucks. Below are helpful links; http://www.vfrdiscussion.com/forum/index.php/topic/33-starter-valve-syncronization-vtec/ Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted February 19, 2014 Author Member Contributer Share Posted February 19, 2014 I have my idle set to around 1.1-1.2k IIRC. I have a multimeter, but not as nice as that shown...and frankly I don't think I have the wrench spinning chops to pull off that job. Thank you VERY much for your input. Years ago I paid a tech to do the synch and it wasn't unreasonably costly, I'm going to call around to a shop I know and trust and see what it might set me back to have them give it a go. I really appreciate the help! Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted February 19, 2014 Member Contributer Share Posted February 19, 2014 You should not have to do the sync again. Check all the usual stuff first, Air box for oil from over filling crank case with oil , Air filter, plugs try some SeaFoam, Charging system , If you do the sync and its out again, MAKE sure to check starter valve that is non adjustable for a loose screw. My primary starter valve that was non adjustable had loosen up and was driving me crazy after the four attempt I reach in small needle nose pliers and the dam thing turned it was loose from the factory. Set it and crimp it so it could never turn again set the starter valves have not touch them in 50,000 miles. Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted February 19, 2014 Author Member Contributer Share Posted February 19, 2014 You should not have to do the sync again. Check all the usual stuff first, Air box for oil from over filling crank case with oil , Air filter, plugs try some SeaFoam, Charging system , If you do the sync and its out again, MAKE sure to check starter valve that is non adjustable for a loose screw. My primary starter valve that was non adjustable had loosen up and was driving me crazy after the four attempt I reach in small needle nose pliers and the dam thing turned it was loose from the factory. Set it and crimp it so it could never turn again set the starter valves have not touch them in 50,000 miles. Sorry man, I was not clear. I did the synch previously on another bike, not this one. To my knowledge it has never been done on this bike. Thanks! Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted February 19, 2014 Member Contributer Share Posted February 19, 2014 Deafinitely do it . Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted February 28, 2014 Author Member Contributer Share Posted February 28, 2014 Ok so...valve synch done, fuel pressure regulator checked...ok, fuel system ok, O2 sensors ok...but the bike is indeed running rich. After a chat with Havagan and the shop owner the next checks are the throttle position sensor and he was going to run the exhaust gas check again to try to narrow it down to which cylinder(s) are running rich if not all of them...but he seemed a bit stumped. None of the usual mechanical causes for rich running appear - it's all factory so not a power commander glitch or such and it's rich across the RPM range. Anyone that has a miracle vision on what's up is welcome to reply. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted February 28, 2014 Member Contributer Share Posted February 28, 2014 Hmm maybe a faulty injector ... Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted March 1, 2014 Member Contributer Share Posted March 1, 2014 And thanks for the update !!!! Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted March 1, 2014 Author Member Contributer Share Posted March 1, 2014 Multiple dyno runs, checks out fine but still 10 - 12:1 FAR across the ROM range. Shop owner totally stumped as O2 sensors seem ok, fuel pressure ok, thermostat ok etc etc. At this point he's suggesting a Power Commander since it costs the same as two Honda O2 sensors (and less than an ECU). Anyone have a tip on a good deal? Anyone want to sell theirs? Link to comment Share on other sites More sharing options...
WGREGT Posted March 1, 2014 Share Posted March 1, 2014 hey Duc2V4...what are you getting mpg-wise? I've been at a consistent 32 mpg since I bought this thing, and I've done the math on every single tank for over a year now. I never even thought it could be any better. I've got Staintunes, PC5, no flapper valve, no PAIR valve... Link to comment Share on other sites More sharing options...
Member Contributer Duc2V4 Posted March 1, 2014 Member Contributer Share Posted March 1, 2014 hey Duc2V4...what are you getting mpg-wise? I've been at a consistent 32 mpg since I bought this thing, and I've done the math on every single tank for over a year now. I never even thought it could be any better. I've got Staintunes, PC5, no flapper valve, no PAIR valve... When I first got my '09 (came with 2Bros exhaust) I was getting about 200-210 miles out of a tank. After I put in the K&N and the PCV (w/de-snorkel and flapper removed) it went down to 180-190 per tank.I ended up doing a flush/fill on the "motor" fluids (Oil and coolant), changed the spark plugs, replaced the snorkel, replaced the flapper, loaded one of the PCV maps on the forum, started using 87 octane and my mileage went up to 190-200 per tank. Obviously, when "sporting it", it's the lesser mileage but on the average it went up. FYI, I am using Rotella T6, Engine ice coolant but I'll have to look up what map I am using. Link to comment Share on other sites More sharing options...
WGREGT Posted March 1, 2014 Share Posted March 1, 2014 I've always used the 87 octane my whole life in everything. I'm getting about 170 a tank, and you are in the 190-200 range. And you removed the snorkel and flapper, then put them back on? I have no idea what map I have on the PC5. No idea how to check or change it either. I'm assuming it isn't Mac based, so I'm at a loss probably. Link to comment Share on other sites More sharing options...
Member Contributer vfrurknee Posted March 1, 2014 Member Contributer Share Posted March 1, 2014 Al, I would check the hot wax unit. Its a PITA very much like a thermostat replacement but there are some ports in the casting that can become obstructed with sediment over time. This can interfere with its travel distance. You might be running like with a partially active choke. Wouldn't affect running temps but plays heck with the mileage. Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted March 1, 2014 Author Member Contributer Share Posted March 1, 2014 I don't believe that's been checked. Where/what is the hot wax unit? Is it similar to the airbox temp sensor? That's what the guy was going to check. Question: if the bike is idling normally (it is) would that still be a factor? Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted March 1, 2014 Member Contributer Share Posted March 1, 2014 Probably not, did the bike ever run right ? Link to comment Share on other sites More sharing options...
Member Contributer vfrurknee Posted March 1, 2014 Member Contributer Share Posted March 1, 2014 Al, The hot wax unit is a small, self contained unit mounted down between the throttle bodies. It is basically an automatic choke. It has an actuating rod that extends or contracts depending on its temperature, as a function of the coolant which surrounds the cylinder containing the wax. When cold the arm movement works on a plate on the starter valve assembly and as the wax melts changing the plates position it changes the fuel enrichment to normal levels. Thought maybe it is not traveling its full range such that while it might appear to be normal there may still be a little choke being applied. I had one of mine completely apart last year. You can check the unit using the hot water tap. Response is almost instant. Ernie PS1. I could be totally off base on this because all my experience is on 5th gens, specifically the 2000 models because this feature was not incorporated on the 98 and 99s. Just assumed it was carried over to the 6th gens. PS2. OK, I went back and watched the video of FM1 and the whole area between the throttle bodies is totally different than what I am used to. This whole Hot Wax Unit thing may be a wild goose chase. Sorry Al. Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted March 1, 2014 Author Member Contributer Share Posted March 1, 2014 Ernie, No apology needed, I really appreciate the help. The guy was indeed going to check the idle thing, based on your comments it sounds like the same thing - the idle/warmup adjuster that's not a choke but kinda is. ;) Link to comment Share on other sites More sharing options...
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