The saga continues... 1979 Spitfire playing dead March 14 1992
In pursuit of my problems ... originally an intermittent
shutdown when warmed up.. then after replacing the coil and the fuel
filter (at the same time).. it seemed to run quite well as long as it
was accelerating.. when running at constant RPM's it would buck. So
in search of this new bucking problem (though I was pretty sure it was
due to an overly rich mixture) I decided to go through the tune-up
procedure as recommended by the people at Motorhead Ltd (Even though
some of the people at Motorhead are really annoying to talk to, their
catalogue is full of good tips for the DIYer). The plan was to:
do a compression check - if high and even
check for air leaks - if none do..
valve adjustment -
ignition - check and gap plugs, set timing, replace old parts.
carburetor - clean, adjust mixture, set throttle, fast idle,
service autochoke.
So I drove to a sunny spot and I removed the plugs and set them aside.
I then removed and set the dist end of the HT lead on the block. I
then did the compression check and came up with the following:
#1: 138
#2: 126
#3: 132
#4: 140
Which seemed reasonable. I checked the gap on the plugs and
noticed one of the ceramic nose pieces was loose and covering the
electrode...(#4, all were brand new (replaced 20 miles ago) Super
Bosch Cu).. so I grabbed an old NGK plug and substituted it. The gaps
were all still good but they were covered with carbon.. so I cleaned
them a bit with the wee spark plug brush on my gapping tool. I put
them in, hooked up the wires and set up my timing light. I then
cranked the engine, the starter turned the crank, but no firing at
all. hmmm.. oh whoops, the spark plug wires are hooked up wrong.. so I
fixed them (I didn't really take note, but I think the bogus
configuration was just a circular shift of the correct hook-up). I
then tried to start, still no good.
"Bloody hell" I said, "what's this machine up to now?" OK
air/fuel/spark. Well I pulled the HT lead from the dist cap and
set it on the block, cranked the engine and observed a yellowy
spark that jumped about 1/2". It was not blue, however. Well that
should ignite a mixture I said. The air filter is new. but I
took it off, same problem. I unscrewed the clamp for the carb fuel
feed and observed fuel pooring out (though I never cranked it
with the line disconnected). Seemed to me that with that much fuel
around I should at least be getting a puff or two.
I then took a plug and stuck it into the block end of the #1
wire. I then set this on the block and cranked and saw a rhythmic
small yellowy/white spark (mind you it was sunny out). So the dist is
turning and distributing sparks. I did the same for number #4. Could
my timing have got way off? So I checked statically by rolling the
car in 4th gear with the ignition on.. and #1 seemed to be firing at
about 5 deg ATDC. It should be 10 BTDC at 750RPM, so that seemed
pretty close. But I tried to get it a little close by rotating
the dist a few degrees and checking again. No change. So i put
it back to where it was.
So I start to think. Well at this point either it is flooded
from the compression test, or the spark isn't powerful enough to
ignite. So I checked the coil which I swapped in last month and
found the resistance to be 2.3 across the terminals (it is supposed
to be 1.3). So I quit for the day, and today I swapped it. I
see a brighter spark with the Allison Chrome coil - as opposed to
an old stock coil, but still it doesn't fire up, just cranks.
I pulled a plug and it looked wet. I sniffed it and it smelt like
fuel, and quite soon after it looked dry.. so it must have been
gasoline, and thus the cylinders are getting fuel.
I notice the battery is only putting out 11.5 volts. When it
is fully charged it is more like 13.3. So I wonder.. it is
also starting to wear down from all the cranking. However the lights,
windshield wipers and fan all still work when turned on at the same
time. Last thing I tried was swapping in an old rotor and dist cap,
there was no change. I pulled the battery and have it sitting on
a charger... and it seems to be accepting full charge.
At some point I looked under the rocker cover and all the
valves seemed to be opening and closing, with nothing obvious
malfunctioning.
I left the car with the butterfly stuck open to aid
in evaporation if the cylinders are flooded. However I had let
it sit overnight - without propping open the throttle.. and nothing
changed.
I did notice and occasional puff come out of the PCV tube when
I was cranking and had this removed. But there was no audible
combustion taking place.
So you experts, what is wrong? Did I screw up the
car by connecting the plug wires wrong? Can I not (for some
weird reason) have different brand plugs in the block (NGK and
Bosch)? Even though the lights, starter and fan ran fine on
the battery, could it not have been supplying enough to the
coil?
Could I still not be getting fuel, even though the
spark plug looked wet? Could it be flooded? How does one
unflood a car anyway? Does a compression test usually flood
the cylinders?
If anyone has a clue, I and B.D. (the Blue "fire spitting" Dragon) would
like to know. Thanks to all in advance.
yours,
Kristian
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