Gas Mileage Issue

[Slappy]

Took the bike in for a new ignition switch. While in I had them check to see if another shop actually put in a new ECU. When I got the bike back my mileage has suffered. I went from an average of 220 per tank to 170 per tank. I was trying to get in the Diag mode to check the CO settings but it wont let me in there. I can get in the D mode but not the CO mode. Any other 07A's that have had their ECU and ignition replaced have this issue? Yes I know to hold both the rest and the select switch then turn on the bike and continue to hold until I see Diag. Release then hold select until the CO comes on. It just wont let me in.

 

[07FJRSD]

dropped about 2 mpg, but bike runs much smoother.

 

[RadioHowie]

Took the bike in for a new ignition switch. While in I had them check to see if another shop actually put in a new ECU. When I got the bike back my mileage has suffered. I went from an average of 220 per tank to 170 per tank. I was trying to get in the Diag mode to check the CO settings but it wont let me in there. I can get in the D mode but not the CO mode. Any other 07A's that have had their ECU and ignition replaced have this issue? Yes I know to hold both the rest and the select switch then turn on the bike and continue to hold until I see Diag. Release then hold select until the CO comes on. It just wont let me in.

I ass-u-me you've done the Barbarian Jumper Mod, since you obviously know about checking CO settings, but if you have NOT done the mod, North American models can't access the CO settings through the Diag Mode until the mod is completed.

Unless there's been a complete change in the ECU setup that I haven't been made aware of, the CO settings are "locked out" in N.A. bikes until the ECU connector is jumpered.

 

[Slappy]

Thanks Howie thats what I needed to know.

 

[RadioHowie]

Thanks Howie thats what I needed to know.

Okay, so you HAVEN'T done the Barbarian mod?

Head over to the Gen II BIN-O-FACTS and scroll just past halfway down the page for some links.

Good luck and good riding.

RH

 

[Slappy]

Ok so I have done the bargarian mod only to find the CO setting to be correct.

What would cause a 20% decrease in fuel economy? The Plugs were changed under 8K ago along with the air filter. I have been using the same fuel from the same station. Tires are 3K old and have proper inflation. The only difference between what I was getting as what I am getting is the ignition switch. I cannot figure out what they could have done.

 

[PA1195]

Ok so I have done the bargarian mod only to find the CO setting to be correct. What would cause a 20% decrease in fuel economy? The Plugs were changed under 8K ago along with the air filter. I have been using the same fuel from the same station. Tires are 3K old and have proper inflation. The only difference between what I was getting as what I am getting is the ignition switch. I cannot figure out what they could have done.

"Maybe" the O2 sensor isn't functioning properly. Disconnect the battery ground for awhile and reset the ECU to base (some will argue that won't work - but it's worth a try). Check the bike's diagnostics and any mechanical connections from the sensor to the ECU. There's tests in the Service Manual to check the diagnostics and sensor. What are your CO settings? Just a SWAG on my part.

Gary in Fairbanks

 

[Foxhuntr]

don't know if this applies to your sitch, but I lost 2-3 mpg with the new ECU. I've got the power commander too. Also lost a mpg or two when I went to the CB +4+2. Now I'm around 38.5, was at 42.

 

[C&C]

Have you had multiple tank fulls that have yielded reduced mpg numbers? Do the tried and true; fill the tank (to a known level), run till on reserve, then fill to the same level and refill to said known level and calulate by hand.

 

[Slappy]

Fox, going from 42 to 38 would be acceptable. I have gone from 42 to 32. My car gets 32.

C&C I have already done that. I actually do that every time I fill up. I guess I am anal that way. When I first got the bike for some reason like clock work the fuel light would flash at 200 miles on the nose like it was programed to do so. This was pretty consistant until I got tired of the throttle surge issue then I attached a power commander with Wallys smoothness map. Throttle surge went away but so did the performance. I delt with it for 10k miles the I removed the power commander. The very next tank once again fuel gauge flashes at 200 miles. I went through 5 or 6 tanks just like this until my ignition switch took a crap. Now the guage flashes at 170.

You did give me an idea though. I am just going to ride the next couple of tanks until empty. Im just going to ignore the guage and live on the trip odometer and see what happens. If all is right in the world I should get 230 out of a tank.

PA1195 I will also try your suggestion on a diag of the O2 sensor just to be sure everything is as it should be.

Thanks one and all for your input.

 

[BwanaDik]

I think I'm having a similar issue with my 06AE.Sounds like we have similar setups, PCIII with Wally's etc. I was riding with a friend this weekend, he was on a 2008 R1200RT. I kept going on reserve at about 170-180 miles, used to be I "thought" I could hold out 'till about 200. I keep the full blown anal retentive log book and record the MPG as calculated by the computer every fill up. I'll go back tonight and recalculate the MPG by hand (since new) and see where the difference showed up. Oddly enough, I seem to recall noticing the gas mileage change after I had my switch replaced too. Do you have the Brodie relay?

Sheesh, nothing more embarrising than having a BMW guy ask if I need fuel every time we stopped. Felt like I had a Harley or something!

 

[Slappy]

Bwana, from what I am reading you are having issues with fuel economy WITH the PCIII connected? I have long since disconnected the PCIII and didnt have fuel economy issues until I had the new ignition installed. You are going to lose some fuel economy with the PCIII since it richens the fuel mixture to help smooth out what Yamaha has leaned out to meet emissions standards. I removed the PCIII due to the fact my $$$ was going towards other accessories instead of a day at the Dyno. You must get the bike Dyno'ed to get max performance from the PCIII.

 

[BwanaDik]

Bwana, from what I am reading you are having issues with fuel economy WITH the PCIII connected? I have long since disconnected the PCIII and didnt have fuel economy issues until I had the new ignition installed. You are going to lose some fuel economy with the PCIII since it richens the fuel mixture to help smooth out what Yamaha has leaned out to meet emissions standards. I removed the PCIII due to the fact my $$$ was going towards other accessories instead of a day at the Dyno. You must get the bike Dyno'ed to get max performance from the PCIII.

Correct. I understand from other posts that I may have lower gas mileage with the PCII connected. I expected that. However, back to the original thread question, I only noticed it after the ignition switch replacement, which makes no sense at all. Will report back after I check my log book.

 

[SkooterG]

Slappy, this is really weird. I don't see how the ignition switch swap could have any effect on fuel mileage. And 32 mpg is ridiculously low for the FJR. Other than fuel mileage, is there anything else you notice different about your FJR?

How many tanks of bad mileage have you had?

Could it be bad gas? Faster riding? Strong winds?

When you fuel up now with your gauge reserve coming at 170 miles, how much fuel does it take to fill?

 

[BwanaDik]

Just went through my log book. I'm really anal retentive about maintance logs from my time as a field engineer in Prudhoe Bay. Discovered lots of turbine and compressor problems there we would have otherwise overlooked had we not had the detailed reports to look back on.

Well, it paid off. I generally write down and reset the MPG every time I fill up. I went back and recalculated all of the MPG's by hand, i.e., miles divided by gallons (duh) as I record all that too. Turns out there is a difference of between 9-12% between the computer calculated MPG and the hand calculated MPG. The hand calculated is always lower and in line with what has been reported here before (about 35-39 MPG-ish) with the addition of a PC-III and the Wally map. So it looks like the computer calculates the MPG based on what it thinks it's sending to the injectors, not what's actually being sent to the injectors. No fuel flow meter on the fuel rail or feed back from the injectors themselves. Sorry if I'm stating something that's been said before, I must have missed it.

So that's why I felt like I had swapped my tank for one from a Sportster this last weekend. The MPG was telling me something different than what was actually happening. I probably only noticed the difference because I was riding with the guy with the 1200RT. So at 25L (6.5 Gal) you should get about 230 miles max out of a tank with a PC-III installed.

Looking back at the dates of the ignition switch swap, there is no apparent difference in MPG and I have many tanks both before and after the switch change to verify any trend.

Also re-confirmed that I get better gas mileage at high altitude. Looks like an almost 10% increase between Houston and Santa Fe NM.

 

[Slappy]

Just ran the tank as far as I could. and I got 202 out of it and put in 5.8 gallons. Thats 35 mpg.

I am going to take a long all highway trip today and see what kind of mileage I get.

I have been driving the same roads and the same general speeds with the same tires, plugs, fuel and oil weight that I have since I have owned the bike. Well not the same plugs or air filter, I changed them at 12k and I am just getting ready to turn over 19K. I have always gotten between 220 and 240 out of a tank of gas and have always put in between 5.4 and 5.7 gallons. Until I got the new ignition switch my fuel idot light never turned on until I hit 200 miles like it was programed to do it. Now it turns on at 150-170 miles even though I have plenty of gas as it turns out.

Before you ask I pulled the two plugs and they look and gap perfect. I also rotated the air filter and it looks fine. Tire pressure was a bit low 38 rear and 37 front.

Winds havent been an issue. It has been colder than usual. In the moring its been in the low to mid 40's and on the ride home in the 60's. Cold usually means better performance but that hasnt been the case.

The only change was the ignition switch and the fact the dealership checked the ECU to be sure it was replaced when I had it done almost a year ago.

 

[JohnTC40]

Just for comparison, my '06A with new ECU, new ignition switch, and CB +4 +3 averages around 45 mpg in a mix of city and highway riding, which is about the same as it was getting before all these changes. This is with 89 octane gas from whatever station I happen to be near when I need it. Maybe I'm just a conservative rider, or lucky, or whatever.