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Posted

I've got a fuel-pressure guage I'm going to throw onto the system to measure mine, but does anyone know what the spec is for the high-pressure side of our EFI system?

 

thx!

al

Posted

This is from the old p7 guzzi manual

 

Electric fuel pump

This is a roller positive displacement pump with the motor submerged in the fuel. The motor is a

permanent magnet carbon brush type. When the impeller is turned by the motor, the fuel is moved from

the intake orifice to the delivery port. The amount of fuel is determined by the rollers which adhere to the

outer ring while the motor is turning. The pump has a check valve to prevent the fuel circuit emptying

when the pump is not running. It is also equipped with an overpressure valve which short-circuits the

delivery when the pressure is over 74 psi to prevent the pump motor from overheating.

Delivery: 26.5 gal/hour at 44 psi with 12V power supply. The pump draws about 4.5 amps.

Guest mcloutier
Posted

This is from the 2001 Sport Manual

"4 ELECTRICAL FUEL PUMP “1” The motorbike is equipped with a volumetric roller type electrical pump whose motor is immersed in the fuel. The motor is composed of brushes with permanent magnet excitation. When the impeller rotates, driven by the motor, it generates volumes which move from the intake gate to the delivery gate. These volumes are delimited by rollers which adhere to the external ring while the motor is rotating. The pump is fitted with a check valve which is necessary in order to prevent the fuel circuit from emptying when the pump is not working. It is also equipped with an pressure valve, which short- circuits the delivery with the intake when the pressure exceeds ~5 bar, thereby preventing the electrical motor from overheating"

 

Not sure if this helps much. I guess you will know what it averages once it's installed.

Posted

The 5 bar is a safety limit on the pump design. Normal running it is much less than that, dictated by the external pressure regulator.

 

The same P8 manual claims 36.8 +/- 3 psi

Posted

My manual says 3±0,2 bar

to convert from bar to psi multiply by 14.508

So, it should be 43.524 psi ± 2.9016

Or for safety and simplicity rather than accuracy of conversion:

41 psi minimum

46 psi maximum

 

Opinion: if fuel pressure gauges are as accurate as tire gauges, beware!

 

And you have probably seen the pressure regulator and gauge here:

http://www.evoluzione.net/

Posted

Yeah, I've got that kit from Evoluzione.

 

The reason I was asking about the pressure was that if I can't find/make a reasonable adapter to mate the OEM regulator to a fitting so that I can mount it remotely... I was looking at a number of aftermarket regulators that might work. But I needed the OEM working pressure, which is about what I susptected.

 

I've got it at the machinist now... so we'll see.

 

thx!

al

Posted

I'm not sure why you want to do this. Putting in an adjustable regulator is a coarse across the board adjustment. The same can be achieved by fudging the air temp sensor or TPS.

Posted

I ran into a guy with a modified California at last year's rally in Prescott Arizona. He had stuffed a Sport 1100 cam in his 1997 California. To let it have enough fuel without fiddling with the electronics, he had the pressure regulator adjusted to a higher pressure. He said he had done nothing else with the bike and that it ran great. I don't see why this would not be a an appropriate method for his bike as everything else except the cam was stock. Mike Rich says the California heads are actually better than the Sport heads, so maybe the guy with the California was on to something.

Posted

Ahh, feels like the old days when playing with Volkswagen fuel injection.

 

The main reason for the adjustable fuel regulator that Evoluzione sells is to adjust the fuel pressure to a stock pressure. A kit is also made for the Aprilia Mille and Falco, I was told that the fuel pressures were so far off from bike to bike that it was impossible to make a chip that would work for them. By using the adjustable fuel pressure regulator, one could adjust the fuel pressure where it should be (stock pressure) and then use the Factory Pro chip. I was lucky enough on my Falco to not need to use the adjustable fuel pressure regulator (though I do have it sitting on my shelf in the garage) with the Factory Pro chip.

 

By increasing fuel pressure you wil richen the fuel mixture across the whole rpm range. I feel the PCIII is the way to go unless your fuel pressure is out of specs.

 

Mike

Posted
I'm not sure why you want to do this. Putting in an adjustable regulator is a coarse across the board adjustment. The same can be achieved by fudging the air temp sensor or TPS.

 

...as Mike pointed out, it's generally to correct for an inaccurate stock pressure as apparently the OEM unit can vary quite a bit.

 

Mine is also sitting "on a shelf" as I bought it on something of a lark some months back when I knew I'd be fiddling with the fuel system :P

 

al

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