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From: rls@ihuxf.UUCP (Richard Schieve)
Newsgroups: net.auto
Subject: re: Fuel Pump??
Message-ID: <2255@ihuxf.UUCP>
Date: Wed, 13-Jun-84 14:56:47 EDT
Article-I.D.: ihuxf.2255
Posted: Wed Jun 13 14:56:47 1984
Date-Received: Thu, 14-Jun-84 00:38:35 EDT
Organization: AT&T Bell Labs, Naperville, IL
Lines: 20

I have no experience with Fiats so I'll relate a similar problem
I had with my 1980 Mustang.  My symptoms were very much the same,
loss of fuel pressure (particullarly when the engine was hot), no
fuel line restrictions and disconnecting the fuel pump at the time
of failure (many failures) showed no output of gas.  The fuel pump
itself pumped plenty of gas from the tank to the pump and right back
down the return gas line back to the tank!!!  It seems that many
newer cars have fuel pumps with internal regulators that are supposed
to keep a constant fuel pressure to the carb by routing excessive
fuel back to the tank.  This is much easier on the float valve in the
carb.  In short, my fuel regulator was shot!.  To make matters worse
the first replacement pump was also bad leading me to distrust my own
diagnosis but the second replacement solved the problem.

A second guess may be a problem with your gas tank venting system
causing more vacuum in your fuel tank than the pump can overcome.
This is easy to test by just listening as you remove your fuel cap
next time your car fails.

				Rick Schieve