[alfa] Re: Biba's cutting out...again

[C2slayman@xxxxxxx]

Biba,
    Ahhhh..........  You're problem might not be intermittent (totally 
random).  It sounds like you've found a correlation with ambient temperature and 
under hood temperature (hot day plus long running time).  So maybe some type of 
vapor lock?
    I forget what type of fuel pump you have.  Is it the stock one designed 
for the carbs (high pressure/low flow) or for the SPICA (low pressure/high 
flow)?  Is there a pressure regulator in the system?  How about a cheap electric 
fuel pressure gauge that you can temporarily wire in just to monitor while you 
try to reproduce the problem?
    By the way, if it is vapor lock, I think the fuel pressure will stay high 
but you will see the glass level low.  What's happening is the fuel is 
boiling in the carb bowl preventing more fuel from getting in - even if the pressure 
is high.
    Sorry, can't help with the Marelli questions.

Cheers,
Charlie
Alfa Vince!

In a message dated 10/22/03 5:14:24 PM Pacific Daylight Time, 
owner-alfa-digest@domain.elided writes:
Date: Wed, 22 Oct 2003 16:22:07 -0700
From: alfacybersite <acs@domain.elided>
Subject: [alfa] Biba's cutting out...again

Without repeating Charlie Slayman's helpful suggestions as to trouble
shooting my intermittent cutting out situation, I'm am going to
concentrate on the fuel delivery situation - which will probably include
(as he suggested) running wires from the fuel pump into the interior and
hook up to a voltmeter.

If one recalls, the 'sight glass' between the two carbs was only a third
full yesterday - both at rest and when idling / revving at standstill.
Just checked and it looks like a level with just one bubble, meaning it
is virtually full to the brim. Started it up, revved it, and it stayed
completely full.

Somehow high heat (it was close to 100 yesterday) combined with a
longish trip (40 miles round-trip) causes the fuel pressure to dwindle
down to a trickle. This is why it is fine going 'cross town' but not on
freeways especially when revving fairly hard while entering a freeway.

Fuel tank was removed and checked about five or six years ago and it was
pristine. I am going to (once again) put on a fresh rear fuel filter.
I'm also going to 'borrow' the condenser from my other MarelliPlex. Am
beginning to wonder if 'condenser' is actually a static supressor since
it is mounted on the coil / heatsink and attaches to the - RUP side.
Should it be of interest it reads (as best I can) - 5U0 (or 5JO) V.efl -
Magneti Marelli -
Made in Italy - FM P (Greek symbol for Mu or m) FO, 3.7 - 4G.

And am about to go on Google to see if I can find an appropriate 4 to 5
pound pressure inline fuel pump (no luck).

I bet anything some of you race guys who run with Weber (or?) carbs know
of a really neat fuel pump.

Biba
Irwindale, CA USA
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