RE: Spica-to-Weber conversion

[Bob Abhalter <gt1300jr@domain.elided>]

By all means disconnect the return line and remove the FI filter canister. 
Use the supply line only and connect it to the carbs with the new/old 
filter-regulator inserted inline - a simple one way circuit is all that is 
required. Also, of course, leave the rear filter in the circuit between the 
tank and the pump.

The previous owner of my 69 Spider left the return line and old FI filter 
canister in the circuit and caused me untold pain and anguish while driving 
the 500 or so miles home from St. Louis to Michigan. The pressure regulator 
inserts some resistance into the line while performing its function. 
Leaving the return line in the circuit gives the gas somewhere to go 
besides into the filter-regulator so the pump works harder than it has to. 
Around town or at low speed this was no problem, but on a hot early summer 
day in southern Illinois, the pump couldn't keep the float bowls full while 
the car was at speed. It is not a good thing to be breezing along the 
Interstate in your newly purchased Spider and begin losing power, crawling 
to a stop by the side of the road to brave the backwash of multiple 18 
wheelers while trying to diagnose the phantom misfire. Of course, by the 
time you stop, the fuel pump has caught up and the problem goes away - 
until you pull away again. Now repeat the process every 20 miles or so from 
St. Louis to Kankakee. When the sun went down, the problem went away 
because the cooler pump got more efficient, so for the last 200 miles all I 
had to contend with was the out of round right front tire and the sloppy 
ball joints and tie rod ends.

But I digress...

Bob Abhalter
Grand Rapids MI


- -----Original Message-----
From:	Marcus Alley [SMTP:alley@domain.elided]
Sent:	Thursday, April 15, 1999 1:55 PM
To:	alfa-digest@domain.elided
Subject:	Spica-to-Weber conversion


I agree with the suggestion that a low pressure fuel pump should be
used when converting from spica to webers.  The PO of my GTV kept the
original fuel pump and used an inline regulator to bring the pressure
down.  As I discovered on the way back from the DMV, this regulator
can shift into a mode where the output pressure is ~0.  While this is
still technically regulated, it's not exactly useful.

So I'm finally at the point where I've ordered a new low pressure
electric pump, and I had a question about the gas line plumbing.  I'll
be moving from the original fuel pump/front filter canister to this
new electric pump and an older, euro-style front filter canister with
the built in pressure regulator.  With this "new" setup, do I still
need a return line to the gas tank?  Or, to put it more stupidly, how
should I hook things up?  Can I just run a line from the fuel filter
cannister to the carbs?  (In a pathetic attempt at a defense of my
ignorance, I'm used to the simple motorcycle setup involving a gravity
feed from the tank directly into the carbs...)

Thanks for the advice,
Marc Alley
Palo Alto
'71 GTV (tensioner wedge and bolt now happily reunited!)
'74 Berlina (still running and somewhere in the west with Ben Dixon)

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