| Symptom |
Diagnosis |
Solution |
| Pump output pressure
is too low |
Incorrect bypass valve setting
(on adjustable pumps), or low voltage to the pump, or a dirty filter |
Adjust bypass valve per pump instructions
(adjustable pumps); check voltage level/charge batteries - pressure is
directly related to voltage; clean filter (on filtered pumps) |
| Pump output pressure
is too high |
Incorrect bypass valve setting
(on adjustable pumps), or bypass valve re-installed incorrectly, or
pressure change due to increased voltage (change from 12 to 16 volt
system) |
Adjust bypass valve per pump
instructions (adjustable pumps); re-install bypass valve properly (call
tech for directions); re-adjust pressure to compensate for different
voltage. |
|
No pump pressure
|
No fuel in tank/cell, or pump
motor incorrectly wired, or blockage in fuel lines, or inaccurate gauges |
Check fuel level - always keep
tank/cell full when racing; check pump wiring against wiring diagram in
tech section of this site; disconnect fuel line at regulator to check for
blockage; check accuracy of gauges |
|
Pump won't run at
all |
Pump motor incorrectly wired, or
batteries discharged, or electric fuse blown. |
Check electrical system for
proper connections and operation |
| Pump seems excessively
hot |
Insufficient voltage, or
excessive aeration |
Check voltage - pump motor works
overtime when voltage is low; check fuel level - when level is low, pump
can suck air from the tank instead of fuel, causing aeration &
overheating |
| Pump seems excessively
noisy |
Excessive aeration of fuel
causing cavitation |
Make sure fuel tank/cell is full
before racing - high volume pumps can actually pull a "vortex"
of air through standing liquid if the liquid is shallow enough |
| Pump seems to pound
or pulsate against regulator |
Aeration of fuel caused by: a
dirty filter, or a failing pump seal, or a malfunctioning carburetor
needle/seat assembly |
Clean filter; replace
needle/seat assemblies in carburetor; replace pump seal or send to factory
for service |
| Pump leaks
at vent hole |
Damaged seal |
Replace seal or send to factory
for service. Seal should be replaced every two years. If a
fuel system has remained unused for a long period of time (3 months or
more) the seal can dry out and become unserviceable. Circulate fuel
through system periodically to 'lubricate' seal |
|
Fuel pressure spikes
noticeable on gauges mounted at the regulator(s) |
Normal operation without
regulator bypass system; expect between 1 to 1-1/2 lb. pressure
fluctuation |
Install optional regulator
bypass system to reduce pressure spiking to within 1/2 lb |
| Pressure
seems to decrease throughout the day |
Possible voltage drop, or gauge
readings are inaccurate |
Ensure that batteries are
well-charged between rounds of racing; heat can effect readings on liquid
filled gauges - use gauges as tuning tools only - remove from
engine after adjustments are made |
| Fuel pressure
fluctuates between rounds of racing at the track |
Gauge readings are inaccurate |
Heat affects liquid filled
gauges. Remove from engine after initial pressure adjustments are
made |
| Car
"lays down" at half track |
Not enough fuel volume for
engine's needs, or not enough pressure to overcome G-force of launch |
Re-evaluate fuel needs of
engine/vehicle combination. Call Tech for recommendations; adjust
pressure (on adjustable pumps) to overcome effects of G-force |
| Regulators
won't regulate; they go "wide open" or "creep" |
Dirt particles or other
contaminant causing regulator's needle/seat assembly to malfunction |
Needs factory repair. The
function of all regulators necessitate the use of clean, filtered
fuel. Make sure to flush fuel lines before using a newly installed
fuel system |
| Regulator(s)
"chatter" |
Excessive air in fuel system;
seal may be damaged and allowing air to enter through motor, or fuel lines
on suction side of pump are not air tight, or pump is pulling air from
under-filled fuel tank/cell |
Check fuel level. Always
completely fill tank/cell before each round of racing. Tighten all
hose ends on the suction side of the fuel pump. Air can actually
"leak in" through improperly sealed joints. If all else
fails, replace the fuel pump seal or send to the factory for service |
| Regulators
leak from vent hole |
Ruptured regulator diaphragm |
Replace diaphragm |
| Fuel spills
over into carburetor(s) |
Incorrect carburetor needle/seat
adjustment, or damaged needle/seat assembly |
Adjust or replace needle/seat
assembly in carburetor |