When good cars don't suck

[Gene Brown <simigene@domain.elided>]

The other night, while driving on the freeway listening to that lovely
Alfa music my 78 Spider suddenly lost power and starting missing badly.
I finally got it home and started checking things.

I know that it takes three things to make the that beautiful Alfa sound,
spark, gas, and air. So, I checked the spark first. Good healthy spark
at coil, timing was correct, all plugs firing. Swapped out cap and rotor
just to check. No luck, engine still ran poorly. Maybe a clogged fuel
filter. I hadn't changed the rear filter in 3 years. Put in a new filter
and still the same. Checked valve timing and it was okay. I was running
out of knowledge of what to check. So I called Charlie Thieriot, the
tech advisor for the Alfa Romeo Owners of Southern California (AROSC).
He indicated that it was not licly that the Spica unit was the fault
since they generally last a long time and also, usually do not fail
suddenly. He suggested I could check for low fuel pressure by
restricting the fuel return line from the Spica unit. Well that test
pretty much eliminated fuel as a problem. 

Well the spark was okay, fuel was okay so that left air. Since I'm not
living in a vacuum (although some will disagree) it was hard to suspect
air as being the problem. Charlie suggested another test. Place my hand
over each of the air intakes while the engine was idling. Cylinders 3
and 4 were sucking (literally, which is good, not figuratively) but
there was no suction from cylinders 1 and 2. It turns out that the roll
pin that connects the throttle linkage the the shaft for the front
butterflies had come out. The vacuum in the intake passages was causing
the butterflies to close so the first two cylinders were having to run
on just the idle air. Needless to say the engine just does not produce
much power in that mode. Replaced the roll pin and everything is running
fine now. I had never thought of the suction test but it is now added to
my list of trouble-shooting tools.

Information I had gotten from the digest and especially the help of Tech
Adviser Charlie Thieriot saved me an large amount of time. Both the
digest and membership in AROC are worth the expense (my check to the
Richard Welty fund is in the mail).

What really puzzled me about this whole incident was that the Alfa knew
I was getting some new tires for it this weekend and it does this. Well
I got the tires but just to teach her who's boss the Alfa is going to
have to be good for a least a week before I put them on her.

Gene Brown
78 Spider (running again)
Simi Valley, CA
Rain today, top has to stay up.

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