Bulletproof Fuel Systems

The first truly new mechanical fuel pump design in more than
 60 years, engineered for high-performance V8 engines.

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Trouble Shooting Installations

The pump and regulator require just four conditions to work properly:

1.    Proper activation by the engine

2.    The proper size vacuum tight, unobstructed inlet line.

3.    A vented fuel supply that is not lower than the pump.

4.    To remain cooler than the boiling point of the fuel.

 The regulator only requires consistent fuel pressure supply to work properly.

 A fuel supply lower than the pump can be compensated for with a check valve at the tank.

Trouble Shooting Pump 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

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. 

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. 

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.

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. 

Trouble Shooting Regulator Installations

Don’t adjust your regulator to compensate for a fuel pressure problem. Return the regulator to the factory setting and trouble shoot the rest of the fuel system. To obtain the factory setting, back the adjuster out until you feel it lose contact with the internal spring assembly, then thread it back in until you feel contact, then 4 turns. This will be 7 PSI.

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. 

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.

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. 

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 

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. 

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. 


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