> Well, now, after warming it up,, if I hit
>the throttle,, it boggs, and fires loudly out the tail pipe and out the
>carbs. If I let up,, it will come back to a reasonable idle,, lopes a
>bit.
> I set the timing at a static 4 deg.
>and put the timing light on it which indicated it was running at I'd guess
>about 20 degrees, and when I rev it up the advance seems to be working
>fine,
Here's a couple.
The total engine timing at full advance should be 33-34 degrees, not 20.
Could possibly be a grunge build up or bad spring keeping your
distributor mechanical advance from working the way it should. I assume
there is no side to side wobble in the distributor shaft. If you pull a
vacume in the vacume advance unit (suck on the tube going in if you do
not own a Mity-Vac) you can see the plate the points are mounted on move
and the vacume does not leak away. When you remove the vacume the plate
snaps back to its original position and not vaguely goes to some place in
the direction of where it was. One possibility is worn distributor
bearings, broken mechanical advance spring, grunge build up keeping the
mechanical advance from advancing and retarding properly.
The second thing that comes to mind:
The engine vibrates a lot and the low tension lead between the base of
the distributor and coil tends to vibrate a lot as well. The vibrations
can fatigue the copper strands and cause it to break INSIDE the
insulation at the edge of a connector crimp. At a visual inspection the
wire looks perfect. But what the distributor sees is a little switch
that is opening and closing quickly as the engine vibrates. Of course
this is in series with the points & messes with the coil's ability to
send a spark and when it does so. The end result is that if the wire is
sitting just right everything seems to work OK then it is like the fuel
flow is almost choked off or the distributor timing has become random.
You are most apt to notice this when going off the throttle to idle, at
higher RPMs and with some random occurrences thrown in for the fun of it.
It can act like fuel starvation, fuel over rich. a broken advance spring
and bad bearings in the distributor. Basically all the symptoms you
describe.
I have been using new striped wire from British Wiring so I have the
correct white with black stripe lead. I just diagnosed this problem for
the second time yesterday. SO that's twice in about a year and a half.
Today I'm going to make a new lead with thicker stranded wire that has
more stiffness. Replacing the lead yesterday afternoon made everything
work perfectly.
I had convinced myself I got a bad tank of fuel, striped and cleaned out
my 45DCOEs twice, added an in line fuel filter to supplement the screen
filters inside the carbs & sediment bowl screen, stripped and cleaned the
fuel pressure regulator and open pumped the fuel line upstream of the
pump.
The only reason I didn't go through the pump and blow out the line from
the fuel tank is that I have a fuel pressure gauge mounted on one arm of
the pressure regulator and it told me I had proper fuel pressure at all
times. But I did clean out the screen on the sediment bowl. I had
recently refilled the fuel tank and put in an entire bottle of red-line
fuel injection cleaner.
I also bought a new distributor. It couldn't have been the wire between
the distributor & coil breaking again, I reasoned because I replaced it
with a new one a little less than a year ago....but it was.
Drives a girl crazy sometimes
TeriAnn Wakeman If you send me direct mail, please
Santa Cruz, California start the subject line with TW -
twakeman@cruzers.com I will be sure to read the message
http://www.cruzers.com/~twakeman
"How can life grant us the boon of living..unless we dare"
Amelia Earhart 1898-1937
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