[alfa] Low Spica Fuel Pressure - Followup

[<roadtrip999@xxxxxxxxxxx>]

Check to be sure the spade connectors at the small fuse block and trunk are
clean and tight. Check the voltage at each connection and that might tell you
approximately where the poor connection is. I assume you've checked the
battery voltage directly, right? Before you wire up a relay system, try
running a heavy gauge wire directly to the fuel pump and see if that cures
your low pressure problem. If it doesn't, then you have a different problem
that even a relay system won't fix. Of course, make sure the grounds are clean
and tight.

For a relay setup, I would just run a new heavy gauge wire direct from the
battery to the trunk of the car. Install a heavy duty inline fuse carrier
somewhere convenient. install the relay in the trunk and shield it from
accidental damage. It'd also be a very good idea, safety-wise, to retrofit an
inertia switch to cutoff the supply pump in case of an accident. Use the
existing electrical supply wire to the pump as the to trip the relay on and
off.

You should be getting darn close to 12v with the battery only and a little
more with the alternator running. The supply pump is very sensitive to
undervoltage. Other causes for low pressure:

1. Failing supply pump (most likely)
2. Leaking pressure relief valve in the front fuel filter
3. Someone installed an L-Jet supply pump as a substitute and didn't narrow
the FI pump outlet restrictor
4. Clogged fuel filter(s) . . . . checked already.
5. Plugged up fuel tank vent creating a vacuum in the fuel tank
6. Excessive fuel temperatures causing supply pump to cavitate
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