Max Voltage Fuel Pump


Information and questions on GL1500 Goldwings (1988-2000)
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RickR
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Location: Piqua, Ohio
Motorcycle: 1994 1500 Goldwing Aspencade, 1984 GL 1200 Interstate, 1984 gl 1200 inerstate (sold), 1982 GL 1100I, 1982 GL 1100I.

Max Voltage Fuel Pump

Post by RickR »



Hello Peeps..

so was having issues with fuel changed out 2 pumps wasn't pump. was ECU an corroded tips.
fixed everything. but now when i start the bike it shows 14volts on the meter at the pump connection.
this is the napa fuel pump everyone says buy.

am wondering if it is ok to run at 14 volts or do i need to check something further. or relay.

Thanks
Silver Dragon



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AZgl1800
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2009 Piaggio MP3 250cc

Re: Max Voltage Fuel Pump

Post by AZgl1800 »

it is a 12V pump, so it will be okay.

as the engine warms up, the voltage regulator will reduce the system voltage to approx 13.6
~John

'02 GL1800
2009 Piaggio MP3 250cc

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ct1500
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Re: Max Voltage Fuel Pump

Post by ct1500 »

RickR wrote:
Mon Jul 13, 2020 3:51 pm
Hello Peeps..

so was having issues with fuel changed out 2 pumps wasn't pump. was ECU an corroded tips.
fixed everything. but now when i start the bike it shows 14volts on the meter at the pump connection.
this is the napa fuel pump everyone says buy.
am wondering if it is ok to run at 14 volts or do i need to check something further. or relay.
Thanks
Silver Dragon
Everyone does not say buy that pump. :? But I am an OEM kind of guy.
With older wiring and resistance I would expect that number to be somewhat less than battery charging voltage, what voltage are you getting at battery?
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RickR
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Joined: Mon Jul 22, 2019 8:31 am
Location: Piqua, Ohio
Motorcycle: 1994 1500 Goldwing Aspencade, 1984 GL 1200 Interstate, 1984 gl 1200 inerstate (sold), 1982 GL 1100I, 1982 GL 1100I.

Re: Max Voltage Fuel Pump

Post by RickR »

ct1500 wrote:
Mon Jul 13, 2020 7:07 pm

Everyone does not say buy that pump. :? But I am an OEM kind of guy.
With older wiring and resistance I would expect that number to be somewhat less than battery charging voltage, what voltage are you getting at battery?
Right now it shows 13.1-13.6. bike running fuel pump shows 14 even.
an i bought what i could afford. I do not have $225.00 right now for the OEM. and I also may need to look at buying a ECU.

Silver Dragon

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ct1500
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Re: Max Voltage Fuel Pump

Post by ct1500 »

That would be a first for me with increased voltage over battery. :?: :?:
Local and need repair help with your 1500, Valkyrie or ST please click contact
Nothing leaves my shop till its' perfect
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AZgl1800
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Re: Max Voltage Fuel Pump

Post by AZgl1800 »

i suspect some bad ground wires...
that just is NOT possible.

If the battery is at 13.3-13.8 ish there is no way the fuel pump is going to have more than that.

The fuel pump is powered by the ECM ( through it actually )
~John

'02 GL1800
2009 Piaggio MP3 250cc

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DenverWinger
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Re: Max Voltage Fuel Pump

Post by DenverWinger »

Since he's measuring voltage right at a running motor might be noise spikes fooling the meter.
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:

~Mark

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RickR
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Re: Max Voltage Fuel Pump

Post by RickR »

AZgl1800 wrote:
Tue Jul 14, 2020 7:24 am
i suspect some bad ground wires...
that just is NOT possible.

If the battery is at 13.3-13.8 ish there is no way the fuel pump is going to have more than that.

The fuel pump is powered by the ECM ( through it actually )
Im gonna take it apart again an look everything over better safe than sorry.

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AZgl1800
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Re: Max Voltage Fuel Pump

Post by AZgl1800 »

DenverWinger wrote:
Tue Jul 14, 2020 7:30 am
Since he's measuring voltage right at a running motor might be noise spikes fooling the meter.
I never bothered to measure the voltage at the B+ terminal on the 1500 fuel pumps.
I just jumpered a wire from the battery to B+ and if it flowed fuel, it was good.
If not, I bought a new fuel pump. Had to do that on my '98SE.

I even bought a 0-10 psi pressure gauge to test the fuel pump....
the bad one made about 0.5 psi

the new one from NAPA IIRC, pushed about 4-5 psi.


~John

'02 GL1800
2009 Piaggio MP3 250cc

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