Trouble Shooting Race Pumps Fuel Pump
Installations
Trouble
Shooting Race Pumps Regulator Installations
Will
Not Prime
Do not attempt to prime your fuel system by cranking over the engine
with the starter.
Carbureted systems require the carburetor float
bowls to be filled and the engine fired off. The system will usually
purge itself of air and obtain proper fuel pressure. Occasionally the
float bowls will need to filled and the engine fired off a 2nd time
EFI systems require the engine be started by
spraying fuel directly into the air intake. The system will shortly
purge itself of air and obtain proper fuel pressure
If the system still will not prime and obtain
proper fuel pressure the likely problem is a vacuum leak or blockage in
the fuel inlet line, or the engine is not properly stroking the fuel
pump.
To test for inlet line problems, replace the inlet
line with a short line on the fuel pump inlet inserted it into a 5
gallon fuel container. Repeat the priming procedure.
If the engine still doesn’t obtain
proper fuel pressure, make sure the engine is activating the fuel pump
properly. Remove the inlet line and fitting from the pump and suck the
fuel out so you can see the piston. Crank the engine over and watch the
piston, it should be moving .340”. If it’s not, the
problem is with the camshaft or pushrod. Back
to top of list
Looses
Prime when engine is shut off
If you engine fails to restart or has erratic fuel pressure for several
minutes after restarting, the likely problem is heat soak or a vacuum
leak in the inlet line.
Heat soak is caused by installing the pump without
the proper heatshield/gasket or improper fuel line routing. The heat
will push the fuel back to the fuel tank, causing the system to loose
prime.
A slight vacuum leak will allow the fuel to siphon
back to the fuel tank, causing the system to loose prime. Back to top
Erratic
Fuel Pressure
Race Pumps do not work well with bypass style regulators. The fuel
pressure will be erratic.
If the engine has erratic fuel pressure for a few
minutes after re-starting and clears up the problem is likely from
loosing prime. Following trouble shooting procedures for
“Looses Prime”.
Fluctuating fuel pressure at idle (unless you have
a bypass style regulator) is usually due to a vacuum leak in the inlet
line. Test this by replacing the inlet line with a short line to a 5
gallon fuel container….if it clears up, you have a vacuum
leak. Back to top.
Lower
Fuel pressure when engine is warm
Fuel pressure gauges mounted in the engine compartment will indicate a
lower pressure when the GAUGE gets warm. The fuel pump and regulator
don’t change. Back to top
Caution-fuel
line size
The Race Pump will not work properly with a -12 inlet line or -10 inlet
lines shorter than 4 feet. Back to top
Trouble
Shooting Race Pumps Regulator Installations
Lower
Fuel pressure when engine is warm
Fuel pressure gauges mounted in the engine compartment will indicate a
lower pressure when the GAUGE gets warm. The fuel pump and regulator
don’t change. Back
to top
Fuel Pressure Drops When
Vacuum Line Is Connected
This is normal. The engine generates intake vacuum when it is not under
load…..at all RPMs. The vacuum reference allows the fuel
pressure to lower when the engine isn’t using much fuel. Back to top
Always set the fuel pressure with the vacuum
disconnected. The fuel pressure will drop at any RPM whenever the car
is “out of gear” or off throttle.
The
Idle Bleed Doesn’t Reduce Fuel Pressure At Idle
The idle bleed is RPM sensitive. If the engine is idling above 1,100
RPMs the fuel pressure will not be reduced. The Race Pumps regulator is
very smooth. Carburetors that have needle and seat assemblies in good
condition will usually idle well at up to 9 PSI. Back
to top
Carburetor
spills over at idle
The Race Pumps regulator is very smooth. Carburetors that have needle
and seat assemblies in good condition will usually idle well at up to 9
PSI. If your carburetor spills over the gauge may be reading lower than
the actual fuel pressure or the needle and seat assemblies need to be
replaced Back to top
Fuel is leaking out the
vent/vacuum reference port.
The diaphragm is leaking and must be replaced. Replacement diaphragms
are available from Race Pumps. Standard Holley and Quick Fuel
diaphragms will fit the Race Pumps regulators as well. Back to top
Erratic Fuel Pressure
The regulator is very simple and cannot cause erratic fuel pressure.
You will need to trouble shoot the fuel pump installation to solve
this. Back to top
Caution
The Race Pumps regulator will not function properly with the fuel
pressure set higher than designated pressures…15 PSI for the
carbureted versions and 75 PSI for the EFI versions. If your gauge is
inaccurate and caused you to set your pressure too high, the
regulator’s internal passage will be restricted and not allow
the regulator to function properly.
If you have adjusted your regulator in an attempt
to compensate for a fuel pump installation problem, the regulator must
be returned to near the “out of the box” setting
before it will work properly.
The Race Pumps regulator will not function
properly with the fuel pressure set lower than designated
pressures…..7 PSI for the carbureted versions and 45 PSI for
the EFI versions. If your gauge is inaccurate and caused you to set
your pressure too low, the regulator will not function properly. Back to top
