[alfa] Re: Fuel delivery problem?

["Dean W. Cains" <dwc@xxxxxx>]

Hi Jeff:

I saw your posting on the AlfaBB, too, but of course you'll get the proper 
answer here ;)

It sure sounds like a fuel delivery problem, and my guess would be the fuel 
pump.  Does your fuel pressure light on he dash work properly?  It should 
be lit when you first turn on the key, and then turn off after a few 
seconds, before you crank he engine.  Since the top of the fuel tank (i.e. 
when it's filled) is higher than the injection pump, even with a bad fuel 
pump you may get enough fuel pressure to fill the injection pump enough to 
run the engine.  Unlike the later cars, gravity forces fuel through the 
filter and into the pump.  I once had a fuel pump fail right after a 
fill-up, and I was able to drive the car the several miles home, as long as 
the revs were kept low.  The pump was completely dead, too.

So, look at the pump.  Is it getting full voltage?  And by that I mean 13.5 
- 14 volts, not ~12.  What about the fuel filter?  They're cheaper than a 
pump, easily clogged with rust and junk from the tank, and can restrict 
fuel flow.  I guessed pump first, because a clogged filter doesn't seem to 
care about fuel level in the tank.  They may clog, but then clear up 
partially after a resting period, though.  Since you said the car sat for 
10 years, I'd also take a peek inside the tank, by pulling the fuel gauge 
sender.  Remember to use a flashlight, and not a match ;)  You may see a 
good amount of rust.  I'm not aware of any Spica injection pump problem 
that would cause the symptoms you've described, and certainly no ignition 
problem.

Report back what you find.

Regards,

Dean
Lutz, FL
'74 & '87 Spider Veloce's


At 07:47 AM 9/4/2003, you wrote:

> Date: Wed, 3 Sep 2003 19:35:43 -0700
> From: "Jeff Thraen" <Jeff@domain.elided>
> Subject: [alfa] Fuel delivery problem?
>
> I recently got my Berlina back on the road after a one year restoration.
> This was proceeded by a 10 year hibernation, but I digress.
>
> Back to the point.  The car runs very well except after using up the first 2
> to 3 gallons of fuel.  Then it develops a miss.  It loses power.  As soon as
> you top of the gas tank, the car runs great.  We drove the car from Los
> Angeles to Monterey for Concorso Italiano like this.  We stopped for gas
> every 50 miles!
>
> So, I suspected that there was something foul in the fuel tank, so today I
> drained it.  Actually I pumped it out.  I just removed the line from the
> front filter and pumped it directly into the gas cans.  Interestingly, the
> fuel ran clear and steady.  I did notice that there were a stream of air
> bubbles that would appear occasionally in the stream of fuel.  I would
> imagine that this is the problem.  I would not think that the fuel injection
> pump would appreciate all of the air in the fuel supply.
>
> Does anyone have a clue as to where this would be coming from?  I have
> replaced all of the flexible fuel lines.  I should also note that there are
> not any leaks, that I can find visibly, but occasionally I do notice a
> slight fuel odor.
>
> Before I go off the deep end and just start replacing everything, can any
> one offer any suggestions on where to start?
>
> Thanks in advance.
>
> Jeff Thraen
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