Might be true but how does the ECU know how much to adjust? Water temp will not change fast enough. When the temp sensor fails, does the fuel or timing change?
The The ECU adjusts the fuelling and ignition timing based on the factory developed map. So for any given air pressure / air temperature / water temperature / engine speed / throttle position combination the ECU knows the injector duration and ignition timing required. With regards to the temp sensor failure, I'd imagine it is fuelling which is affected predominantly. A cold engine generally needs more fuel, the ignition timing requirements don't change greatly. Dave
Well on a carbed bike if you don't choke it when cold it won't start. With the efi bikes some have high idle lever but unless it does make some adjustment, I don't believe it would start. At very least, since it makes adjustment for temp., if the bike get's hot (lean) (from altitude) it would make adjustments for that. Yes??
I don't have a FI Husky but have years of experience with EFI on primarily Japanese streetbikes using both Mikuni and Keihin systems. EFI never becomes a carb in basic delivery. It always uses a base, pre-programmed map, and then uses sensor inputs to offset the map. Racemap 2 would simply be a different base map, still offset by sensor inputs. All systems I've seen use an IAT sensor, intake air temp, in the airbox or velocity boot before the TB, to make changes for air temp. The CTS coolant temp sensor makes changes based on engine running temperature. The MAP, manifold absolute pressure, sensor has taken the place and function of what is still used on touring bikes called the BARO sensor (barometric pressure, or altitude). A MAP initially gives the ECM the barometric pressure before the motor starts, then reverts to manifold pressure info. Fuel rails used to have a regulator on the return line that varied with manifold pressure, which slightly varied the rail fuel pressure. Now, the MAP takes it's place and accounts for changes in manifold vaccum by offsetting injector volume instead of rail pressure, and fuel pressure is constant. On a bike that is started at a low altitude and run up many thousand of feet, it may be necessary to shut the bike off and restart it, to recalibrate the barometric setting the ECM is using. It's not normally an issue on commuter bikes and offroad bikes as they generally don't vary altitude too much in a single ride. touring bikes like Goldwings, still use both a MAP sensor and a BARO sensor, as it is likely to go long distances with the possibility of large altitude changes. Current, fast processors have also allowed the MAP to take the place of cam-position sensors, as the ECM can tell what stroke it is on by evaluating manifold pressure changes. Cool stuff.
Marc, you are saying that EFI does all that stuff, but the Mikuni system on the 08-10 EFI Huskys, does that system do all that? It's been my assertion that whatever adjustment this system makes on the fly (after PowerUp and lambda sensor removed) is minimal, if any at all. Why would an EFI system that measures barometric pressure at key on and coolant temp need to have a cold start lever, like my 2010 Husky has, shouldn't the system read the cold engine and program for the fuel that the bike needs, without having the user choke the bike manually? I live and ride at about 1000 feet elevation and the bike runs rich, with an apparently generous map. When I take the bike to 4000 feet in NM and then ride it to 10000 feet in the course of the day, how much leaning out can I expect the system to do? As much as is needed to maintain the programmed map or a percentage cut off the base map and how does it actually decide how much fuel to cut with no sensor in the exhaust? Does it just cut a percentage from the base map? With this EFI bike, I have not seen hardly any change in my MPG at 4000-10000 feet elevation like I used to see with my re-jetted carb bikes when I took them to the mountains. I am just skeptical that there is any real change going on with my fuel mixtures and just because the bike is SUPPOSED to be doing it....doesn't mean that it IS doing it..
Again I haven't owned or worked on them but I doubt that Mikuni re-wrote their EFI book for those. Cold-start lever is common on simpler systems in the interest of weight, cost, and complexity. Someone earlier mentioned the idle-air bypass screw to adjust idle speed? The Cold-start lever is an additional air bypass, or some simply kick the throttle plate a bit, like holding the throttle 1/16 or 1/32 open. Bikes that don't utilize a cold-start lever, all have a stepping motor called the Idle Air Control Valve IACV. It varies the size of the idle-air bypass orfice, and starts out large and steps down as the machine warms up. As for how your machine responds to temp and altitude differences, a machine can only be as good as the firmware programmed into the ECM. Those machines were known to be flawed in that area. IMO Mikuni EFI is bogus compared to Keihin, as a rule. Again, just my opinion backed up by my years as a lead tech at a full-line dealer. If your machine seems "rich in general", the easiest way to offset the whole fuel map is with the TPS setting, basically tricking the ECM into thinking the throttle is a few percent LESS open than it really is. Of course, fuel maps are rarely wrong in a linear fashion, they are rich here at this RPM and opening, and lean at this RPM and throttle opening, often all over the place. Throw in some mods and it's a real crapshoot. Thats where EFI controllers like the Powercommander5 and the Bazzaz system are really great tools.
Does this translate into "the Mikuni EFI system probably does little to no adjustments on the fly based on variables such as barometric pressure, air density and temperature"
I elected NOT to do the P/U upgrade and just did the JD EFI to have better control on the fueling. I asked myself the same questions, IF I remove this? how will the ECU control the altitude complensation. So far, I am happy. The Bike has more power than I will ever need.
I'm curious why people think FI systems don't do anything" and yet the bike runs pretty well like mine, from sea level to 10,000 feet. I'm also curious if carbed bikes need jetting changes at altitude, why sensors etc do not serve that same purpose of adjustment. Q. How do bikes run without O2 sensors.? O2 sensors are emmision control devices. It does assist in fuel mixture calculations on cars , but not required as the fuel delivery system on the bike is similar but yet different. it has a predetermined set of fuel trims or tables that is programmed into the CDI box. It also uses the TP sensor, the IAT sensor, Coolant temp sensor, BARO and MAP sensors for real time fuel adjustments. You will find o2 sensors on anything that has a Cat converter where the emmissions must be maintained at certain levels while the Cat does its job reducing certain gasses and converting them to co2 and oxygen. 2 years ago http://answers.yahoo.com/question/index?qid=20100923153346AACiY0U
In Idaho we sit around 3500 feet. And some of the mountains that I have had the pleasure of riding are up in the 9-10,000'. My carb bike (WXC 410) did really well with out any issues. And my 2008 TE510 seems to run so much better with the JD Tuner.I think the dealer took the CAT out before the bike was delivered. Really it was the low end surge that caused my the problems. IF you tried to blip the throttle, it would stall of a split 2nd then take off like a mad hatter. It was alot to hang on to. I agree with you on all the EFI you spoke of. The sensors do regulate what that system is doing. Glad I have mine the way it is now.
I just got back from a 2 day ride at 4000-6000 feet elevation. I got 35mpg, the same 35mpg i get at my home of 1000 feet elevation. I agree with MotoMarc36 when he says "IMO Mikuni EFI is bogus compared to Keihin, as a rule." meaning (to me) the Mik EFI does very little if anything as far as adjustments on the fly to the fueling.
"I elected NOT to do the P/U upgrade and just did the JD EFI to have better control on the fueling. I asked myself the same questions, IF I remove this? how will the ECU control the altitude complensation. So far, I am happy. The Bike has more power than I will ever need" if you fit the jd without doing the power up then the ecu and o2 sensor will adjust what you yourself have changed. basicly with o2 sensor in (non PU) then fueling is closed loop, ie the o2 sensor and ecu keep fueling in check within a set criteria. by removing o2 sensor and plugging in resistor in its place you go to open loop where you have the 3 settings you can change in ibeat to adjust fueling. jd tuner adjusts fueling in addition to these 3 base settings. to fit a jd tuner on a non pu bike is a total waste of time and money and achieves absoultly nothing.
Good inputs on this thread. Even though Mikuni may be a little "bogus" in that the system may not be as refined as the Keihin the 2008 TE/SM 610 Repair Manual states in Sec M pg72 that: "The items to be considered for the correct output of the fuel in every condition of use of the vehicle are the followings: - Air temperature in the intake manifold; - Engine coolant temperature; - Atmospheric pressure in the intake manifold (in the current position and altitude); - Throttle opening percentage; - SM 610: Vehicle rollover; - Rich or lean combustion mixture (O2 sensor); - Battery voltage; - Sensors source; - Current gear position; - Pulse width of fuel injector; - Ignition coil; - O2 heater. " The diagnostic software "DIAGNOSIS SOFTWARE KIT" (see on page M.76) allows the check of the above mentioned parts in case of fuel injection system malfunction. (IBeat) So, the two systems have basically the same inputs. Senior Husky Rider, I think your ECU is making these inputs and adjustments as you go to altitude. Your 35 MPG over the ride does suggest that your bike is running fairly rich somewhere in the fuel curve. One would expect that we would get better mileage at higher altitudes as the mixture leans out. I'm not sure how high we'd have to go to really notice this. This thread has pretty good stuff for all of us. It would be nice if we could get an actual Mikuni and Keihin engineer on here as an inmate. There is still a lot of conflicting input on the FI forums...........but we're learning. A pretty Old Husky Rider myself(70)..........and just learning my 2008 TE610
One of the most common sensor failers is the Eng coolant temp sensor. One responder to a post stated he had heard from a dealer the ECU assumes an overheat condition if it is not receiving input from the Eng Temp sensor and turns the radiator fan on at all times "and possibly enriches" the mixture curve for cooling.
There are two different things going on here. One is the fact that the bike has to adjust the FUELING based on the air density changes. The other issue is that, at higher elevations (thinner air), you need a larger throttle plate (or bypass) opening at idle to maintain the same idle speed. Many EFI bikes don't have automated idle speed control, simply because the cost and complexity is high, while the benefit is relatively low. So, when you go up in altitude, you may need to bump the idle a bit if you want to have the exact same idle speed. This does NOT mean that the bike isn't compensating with regard to FUEL, though, it is! Does the cold start lever on the TB effect the FUEL (ie, does it enrich the mixture), or does it simply increase the air bleed (high idle)? My Ducati is fuel injected, and it definitely compensates for low coolant temps by enriching the mixture. However, you still have a (handlebar mounted, in this case) cold start high idle "lever," which you use to increase the engine speed on a cold start. I suspect that the husky lever is an air bypass only, and it just lets you have a high idle on cold starts so the engine will run better and warm up faster until it has heated up somewhat. Again, this does not mean that the bike is not compensating the fuel for the changes in engine and air temperature; it is. I know that on my buddy's 310 (FI), the handlebar cold start lever is just an air bypass, not an enrichment. Same for my Duc.[/quote]
I bought my bike with the power up mods already installed. It ran fine in all conditions the first year. The air intake boot somehow came loose causing unknown problems for over a year. found that and fixed it. This spring I got water in my sparkplug boot... fixed that but it now will not cold start with out twisting throttle, even though it is FInjected, and pops a lot on deceleration but the worse thing about it is it runs progressively worse as I climb above about 3200 feet... eventually it just wont rev up.... as I lower the altitude it runs better again. Riding season is here and I can't find anyone to work on this for me in the Northwest area... can someone help? I unplug the TPS and the fan turns on and the bike wont start so I know that seems to be working... after that I got nothing... it there possibly water in some other component? the sparkplug boot happened after washing the bike.... thanks.
