"Runs out of gas" with a gallon left - blame the PCV?

[BrianK]

Here's a new one (to me):  Installed a Power Commander V on my wife's 07 Nightster.  Started it up and took it for a test ride.  Ran fine, but after half a mile the low-fuel light came on and a few minutes later it "ran out of gas."  Checked tank, still maybe a gallon left.  Started right up.  Then did it again.  By that time I was near a gas station so I filled up the tank.  Took 2 gallons (just under) in a 3 gallon tank.  Rode it another mile, no problems.

Bike has 15K or so miles and has never done this before.

Since it happened immediately after installing the PCV, I'm inclined to blame it, but I dunno.

[Panzer]

Did you install the wide band O2 sensor in the exhaust?

[BrianK]

Nope.

[Panzer]

It should have come with the Commander.

This was taken from the Commander site:

AutoTune for Power Commander V
The Auto Tune kit monitors the fuel mixture (by installing the included Wide Band O2 sensor in the exhaust). It then sends this information to the Power Commander V and automatically corrects it while you ride. Each map that we offer has preset Air/Fuel ratio values included that we find to be the best overall settings. This lets you simply plug in the unit and let it do the work. For Harley Davidson models we ever monitor and adjust each cylinder individually for increased precision as on these models required fueling can vary significantly between the front and rear cylinder.

[BrianK]

Only if you buy the optional Autotune, as I understand it.

[Sky]

Temp unplug the PC, Test ride, you'll know.

[BrianK]

Temp unplug the PC, Test ride, you'll know.

Thanks Sky.  Gonna see if it happens again and if so do just that.

Now that I think about it, symptoms sound like the dread pinholes in the submerged EFI fuel line issue.... I'll keep a look out for that too.

[splitting_lanes]

Did you figure this out?

What was the issue?

[Nowhereman]

I'd blame the fact that your running FI..
Carbs rule..

[Jackal]

The 3.3 gallon tank on the Nightster has a fuel pump inside with the pickup being near the middle of the tank. You can really only use about 2 gallons before the low fuel light comes on, somewhere around 80 mi. with the PC-V I'd guess, based on personal experience. I almost always top off with 2.2 gallons, most ever was 2.4 IIRC. There is basically about a gallon left in there that can't be picked up by the pump...stupid is it not, but it makes the 2.2 gallon tank on my carb'd Sporty seem like a good idea since I basically get the same out of both.

[BrianK]

I'd blame the fact that your running FI..
Carbs rule..

Couldn't agree more.  I love carbs...and points!  Won't strand you by the side of the road....or if they do, you can usually jury-rig enough of a fix to limp home.

[BrianK]

Did you figure this out?

What was the issue?

Haven't had it happen it again.  Not sure why, to say the least!