Mallory Ignition Mallory ELECTRIC FUEL PUMP TROUBLESHOOTING GUIDE - Manual (Page 2)

FORM 1485M
12/03
Made in U.S.A.
Printed in U.S.A.
MALLORY IS A DIVISION OF THE MR. GASKET PERFORMANCE GROUP
10601 MEMPHIS AVE. #12, CLEVELAND, OH 44144
216.688.8300
FAX 216.688.8306
www.mrgasket.com
2
Q.- When I first hit the throttle hard, the pressure
drops then comes back up. Why?
A.- The pump has to catch up to the demand. The
problem would not exist if the car had a return
(bypass) style regulator. The fuel would always
be flowing.
Q.- When I adjust the fuel pressure, it’s fine when it’s
cold, but then it starts dropping off. If I let it cool
off, the pressure comes back up. If I readjust it
hot, then I have too much pressure cold. What’s
going on?
A.- This is a classic problem when there is a liquid
filled gauge mounted on or near the engine. The
pressure isn’t changing, it’s the gauge reacting to
the underhood temperature. To prove it, start the
engine with everything cold, then blow hot air
from a hair dryer on the gauge. You can watch
the pressure reading drop. It’s just the nature of
liquid filled gauges and hot engines. Try to mount
the gauge away from as much engine heat as
possible.
Q.- I want to run a return style system, but there isn’t
another hole in the tank. What can I do short of
welding in a fitting. Can I dump it back into the
feed line?
A.- Run the return into the fill neck if you have to, but
you cannot either put it into the feed line or the
bottom of the tank. Remember to keep the return
line above the fuel level in the tank.
Q.- Every Spring, I have to take apart my pump and
regulator apart. I store my car in the winter in a
garage. Why the sticky mess?
A.- The higher octane the gas, the quicker it
evaporates. If you leave fuel in the system, add
one of the many additives available and put in a
regular pump gas. Racing type gasoline
evaporates quickly and leaves a sticky mess that
will gum up everything. Just remember to put the
right fuel in before you go out and stand on
the throttle.
Q.- I took my pump apart, cleaned it up and tighten it
back up. Now it doesn’t want to run. What did I
do wrong?
A.- When you put the pump assembly back on the
bottom of the motor, be sure to draw both of the
screws up slowly and evenly. Do not over tighten
them. Make sure all of the pieces go back on the
same way they came off. Putting a grease pencil
mark down the side of the pump housing is the
simple way to make sure that you don’t put it
together backwards. They’ll fit, but they won’t
flow the fuel right.