PC III Mapping question

[Ack535]

OK, so I have a 2005 FJR with the following set up:

1. PC III with "Smoothness Map" & O2 sensor disconnected

2. Airbox mod with K & N Filter

3. Two Brothers slip ons

Bike runs really great and fast, but is there a quick and easy way I can restore the bike to the default zero map for better MPG for a long trip. I see there is a ground lead up to the battery. Can I just disconnect the lead or is there another easy way to return to the zero map.

Also I was thinking about re-connecting th O2 sensor when I go back to the zero map for better MPG.

As the bike sits I get around 38 to 40 MPG. I would like to increase that number to around 45 ish for a long trip I have planned this coming May.

Thanks for your input!

Pete

Here is a pic of my bike:

 

[extrememarine]

You can get a zero map from the pciii website here.

I had a custom map in my '04. Never really saw any significant mileage gains to be worth giving up the smoothness of the custom map. Easy to play with though, just plug & play /w usb cable and a laptop.

-wr

 

[kulwen]

PowerCommander LCD Display

It will be a couple hundred bucks, but lets you change maps without a connecting to a PC.

 

[FJR Flyer]

It will be a couple hundred bucks, but lets you change maps without a connecting to a PC.

$300? For a long trip, I'll just hook up the laptop and swap maps. Costs more than what I paid for the PCIII itself.

 

[Aasland]

If you disconnect the ground wire for the PC3 your bike won't start.

I installed one of these to switch between maps:

https://www.powercommander.com/powercommand...nction_hub.aspx

(that's the hub with the map switch).

Then to make it pretty, I installed the Lamptron push-button switch which UselessPickles found:

https://www.fjrforum.com/forum//index.php?s...&hl=crazypc

(note the PC3 switch doesn't ground like the Autotune .. to get the switch installed correctly and light up you'll need to get thinkin with a relay).

I use this setup to switch between the zero map (efficiency) and the Dynojet map.

Another option is to run one map - merge the two maps, so that the zero map values are used at less than 30% throttle, and the dynojet map everywhere else.

 

[Grumpy]

Couldn't you just switch the Oxygen Sensor in and out. In and the PCIII is ignored, out and you have your custom map.

 

[Aasland]

Couldn't you just switch the Oxygen Sensor in and out. In and the PCIII is ignored, out and you have your custom map.

Nope.

https://www.fjrforum.com/forum//index.php?s...=120477&hl=

Summary: PC3 + O2 sensor = engine codes + hesitation/bogging.

 

[wfooshee]

The ECU doesn't bypass the PCIII, it chases it around. The PCIII says "add 4 to the ECU's fuel map" and the ECU sees rich, and leans out. The PCIII will add 4 to that, still, but the ECU settles on something that makes it happy.

Then the rider does something nasty like changing the throttle.

The ECU is constantly "correcting" the PCIII's map adjustments, and if that makes it go somewhere out of its range, it'll throw a code.

 

[Grumpy]

Could there be a difference in the way Gen I vs. Gen II works? Big differences in injection systems and oxygen sensors.

 

[wfooshee]

Not sure, but I don't think so. The PCIII does nothing but modify the ECU's fuel mapping by raising or lowering the squirt volume based on its RPM vs. throttle-position table: At such-and-such RPM and such-and-such throttle percentage, add or subtract this amount of fuel from what the ECU called for. It has no feedback, and no monitoring capability, just modifies the flow.

Plugging up the O2 connector gives feedback to the ECU that it can use to try to "correct" the modified fuel flow, which is why I said it "chases" the PCIII.

Differences in Gen1 and II aside, the PCIII's function is the same in both. Modify the fuel flow according to a table of RPM vs throttle position.