Testing fuel pumps
05-07-2008, 01:49 PM
#1
3rd Gear Member
Thread Starter
Join Date: Dec 2006
Location: Bullard, Tx.
Posts: 533
Testing fuel pumps
Does anyone know how to test the fuel pumps for psi and volume with the motor out of the car? I would like to test the new setup (dual gt40 pumps dual -6 outlets and -8 line to the firewall) now before the motor goes in and the car goes to be tunned.[/align]
05-09-2008, 01:37 PM
#2
6th Gear Member
Join Date: May 2006
Location: Nicely done
Posts: 11,881
RE: Testing fuel pumps
i noticed you're not getting very helpful
answers on the other 2 forums where
this was also asked, so i thought i'd give it
a shot.
since i don't think you can easily simulate a
duty cycle command from the pcm to
the FPDM(s), you might have to use a variable
DC power supply, to control the pumps
directly.
you would open the control voltage line between
the FPDM(s) and the pump hat and control
the pumps there (for your flow tests).
i would feel confidant doing such a procedure, but
if you don't, then it's not something you
should try
there's also the possibility, that i'm way
off base here and that there is another
much simpler and smarter way to do it....
answers on the other 2 forums where
this was also asked, so i thought i'd give it
a shot.
since i don't think you can easily simulate a
duty cycle command from the pcm to
the FPDM(s), you might have to use a variable
DC power supply, to control the pumps
directly.
you would open the control voltage line between
the FPDM(s) and the pump hat and control
the pumps there (for your flow tests).
i would feel confidant doing such a procedure, but
if you don't, then it's not something you
should try
there's also the possibility, that i'm way
off base here and that there is another
much simpler and smarter way to do it....
05-09-2008, 01:52 PM
#5
2nd Gear Member
Join Date: Jul 2007
Location: Indianapolis, IN
Posts: 468
RE: Testing fuel pumps
ORIGINAL: hammeron
yes and you have to test it
on your tongue before
installing
yes and you have to test it
on your tongue before
installing
05-09-2008, 02:24 PM
#7
Cut & Paste Expert
Join Date: May 2007
Location: NW Arkansas
Posts: 13,322
RE: Testing fuel pumps
Itsthe duty cycleof the pump to control fuel rail pressure.
Its not voltage, Hamm.
12V constant is a 100% duty cycle so
hooking it to 12V constant would simulate
a 100% flow rate or what the pump is capable
at 100% duty cycle.
We (S197s) use a returnless fuel system
and the FuelPumpControlModule gives the
pump 12V but with a specific duty cycle
according to fuel rail pressure.
I have no idea what the 9V battery is all about.
It does not have enough amperage to drive a pump.
Its not voltage, Hamm.
12V constant is a 100% duty cycle so
hooking it to 12V constant would simulate
a 100% flow rate or what the pump is capable
at 100% duty cycle.
We (S197s) use a returnless fuel system
and the FuelPumpControlModule gives the
pump 12V but with a specific duty cycle
according to fuel rail pressure.
I have no idea what the 9V battery is all about.
It does not have enough amperage to drive a pump.
05-09-2008, 02:56 PM
#8
6th Gear Member
Join Date: May 2006
Location: Nicely done
Posts: 11,881
RE: Testing fuel pumps
not bad db, but let's see what the
service manual has to say about it
[IMG]local://upfiles/37808/977097EB0C734E2FB9AEB41AA6DB75D9.jpg[/IMG]
service manual has to say about it
ORIGINAL: 157db
Itsthe duty cycleof the pump to control fuel rail pressure.
Its not voltage.
12V constant is a 100% duty cycle so
hooking it to 12V constant would simulate
a 100% flow rate or what the pump is capable
at 100% duty cycle.
We (S197s) use a returnless fuel system
and the FuelPumpControlModule gives the
pump 12V but with a specific duty cycle
according to fuel rail pressure.
Itsthe duty cycleof the pump to control fuel rail pressure.
Its not voltage.
12V constant is a 100% duty cycle so
hooking it to 12V constant would simulate
a 100% flow rate or what the pump is capable
at 100% duty cycle.
We (S197s) use a returnless fuel system
and the FuelPumpControlModule gives the
pump 12V but with a specific duty cycle
according to fuel rail pressure.
05-09-2008, 09:03 PM
#9
3rd Gear Member
Thread Starter
Join Date: Dec 2006
Location: Bullard, Tx.
Posts: 533
RE: Testing fuel pumps
So to ck for leaks at the pump at least would I be able to connect 12v to the pumps with the line closed an watch th fuel psi gauge so not to make to much psi and with that being said what would the max psi be that you guys would go to just to test for leaks? And yes Hammeron I am not getting very many replies on this maybe its becouse it cannot be done correctly IDK but I do thank you guys for the help.
05-09-2008, 09:11 PM
#10
6th Gear Member
Join Date: May 2006
Location: Nicely done
Posts: 11,881
RE: Testing fuel pumps
well the reason i suggest a variable
DC power supply, is so you can bring the
pump control voltage up slowly and
methodically.
if you're just testing for leaks to say the
engine bay, then you could bring the voltage
up, until your pressure gauge reached
your desired test level ie 30 - 50 psi
DC power supply, is so you can bring the
pump control voltage up slowly and
methodically.
if you're just testing for leaks to say the
engine bay, then you could bring the voltage
up, until your pressure gauge reached
your desired test level ie 30 - 50 psi