And the winner is.... (was 3cyl GTV)

[Robert Brady <bobb@domain.elided>]

Thanks to everyone who replied with suggestions for my ailing, 3cyl GTV.

As it turns out, the check valve in the outlet for the #3 fuel line was
broken in two. The check valve keeps the fuel line at pressure.  If the
fuel line doesn't maintain pressure, you either don't get fuel through
the injector and/or get a poor spray pattern.

Recall that the injector for that cylinder also was broken internally...
go figure. Also remember that I discovered the bad injector after
replacing the re-brazed bellcrank that I broke at Lime Rock in
November.  My faith in the reliability of these systems is being
seriously challenged.  But, I guess you can't expect too much from a 25
year old system.  Even so, I don't need excuses for why things fail. I
just need a bulletproof system as the car is seeing more and more track
time.  Webers are looking like a simpler,  more reliable if less elegant
way to put fuel into the cylinders.

As far as causes for the failures, it's not at all clear to me.  The
check valve didn't show any signs of scoring, pitting or corrosion which
would indicate it binding leading to it breaking.  The shaft of the
check valve came out with no problem.  I suspect that one failure led to
the other, but I can't quite figure out which one came first.  Nor is it
clear to me how one could cause the other to fail.

The Alfa specialist down the street from my house (Woody at Alfa
Performance Center)  wins the prize for the correct diagnosis.  I'm
assuming these are pretty rare failures since he said he's had to
replace a grand total of about four injectors in 30 years of working on
Alfas.  He mentioned that he's had the check valves leak, but never said
anything about one breaking.  I guess I should be playing the lottery,
as lucky as I seem to be right now.

At any rate, the problem is 95% solved.  The line holds pressure
reasonably well, certainly much better than before, but not perfectly
yet.  The replacement valve needs to be lapped into place to get to seal
properly.  (Apparantly, AR had a service bulletin on this some time
back.).  So, hopefully I'll lap the valve later this week and be back in
business by the weekend.

Thanks again for everyone's help.  If I had a camera with a macro lens,
I'd take some shots of the broken bits... but I don't.  At least this
will make an interesting article for the next newsletter.

Bob Brady, DVAROC
www.dvaroc.org
Yardley, PA
'88 verde (shakes no more)
'74 gtv (3.95 cyl.)

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