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Clymer Manual
Chapter 7 page 237
bottom right of page. #4

Quote

"The fuel pump is cooled and the bearings are lubricated by the fuel passing thru the unit. Do not run the fuel tank dry. If the fuel pump is operated without fuel, its bearings will be damaged.
If damaged the fuel pump must be replaced as a unit."

I believe the person whose bike would not start for four months just went thru this.
 

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Just curious, how can you run the bike without fuel?
 

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bjedruszczak said:
Just curious, how can you run the bike without fuel?
If you turn the ignition on the fuel pump will run until it has reached prime pressure on the fuel rail. If there is not sufficient fuel the pump could run until it burns up.

John
 

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Wrencher Extraordinaire
2005 K1200LT
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AlaskaFish said:
If you turn the ignition on the fuel pump will run until it has reached prime pressure on the fuel rail. If there is not sufficient fuel the pump could run until it burns up.

John


It is a timed event from the Motronic controlling the fuel pump relay. That relay also feeds the 12v to the coil, injectors and the purge valve. There is no feedback to the Motronic (electronically) on fuel pressure. If you check the injectors the 12V goes away when the fuel pump stops after a key on event.
 

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jzeiler said:
It is a timed event from the Motronic controlling the fuel pump relay. That relay also feeds the 12v to the coil, injectors and the purge valve. There is no feedback to the Motronic (electronically) on fuel pressure. If you check the injectors the 12V goes away when the fuel pump stops after a key on event.
Well I guess I stand corrected then John. Sounds like they may have designed a safety into the system that I had not even thought about. Bottom line is that you do not want to keep running the pump if there is no fuel available.

John
 

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Basically all fuel injected cars have used this exact type of fuel pump system since the mid 1980's. I think it is a pretty bullet proof design. While it is admirable to treat your motorcycle kindly, I don't think this is a scenario worth missing mass quantities of sleep over.

Does anyone here worry about running their Buick's fuel pump out of gas?

My $0.02

Spaghetti
 

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I try to keep enough fuel in the tank to submerge the pump.

I have direct experience with this.

A friend's wife always put in $5 of fuel in her van.. (that would put 3 gallons or MORE back then...)

This kept her van always "bouncing" on the "E"... (she was afraid of someone stealing fuel.)

We replaced the fuel pump every other month for a year... finally "Auto Zone" refunded his money saying.. "We can no longer honor the replacement because something is wrong with your installation."

ER... ok....

We asked her to start keeping at least a 1/4 tank of fuel... Guess what? The van got another 100k miles without the pump failing...

Sheer luck...? Nope.
 

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x2........The pump really does need to be in the gas..........It's not like the gas in the bottom of the tank isn't going to get used, but I always keep my tank topped off just because of the EFI.........$ .02.........
 

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The early electronic fuel pumps for carburetors were exterior mounted. Everything is in the tank now as far as I know. Anyway I've never seen a newer injector pump that wasn't in the tank.
 
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