Over the weekend I spend more time checking the snake's intermittent
stumbling problem. I couple of people speculated that the float inlet
valve might be sticking. This seemed reasonable so I tried to verify
this by performing a simple test suggested by one responder. This
consisted of holding the throttle wide open while the problem was
occurring. The idea was that more air would lean out the overly rich
mixture caused by the flooding. The results were mixed, or at least not
quite what I expected. I was more or less able to keep the engine
running this way, but only because it caught briefly ever second or two.
Perhaps the higher inertia of the faster turning engine is what kept it
chugging along rather than the "improved" mixture. Still, it wasn't
dying completely which supposedly implied that fuel starvation wasn't
the problem. I also watched to see whether or not fuel was "pouring
down the throat". While I wouldn't call it a flood, there didn't seem
to be any shortage in the throat and the accelerator pump was obviously
working. While this wasn't conclusive proof in my mind, the sticking
valve scenario still seemed creditable to me; ally considering massive
flooding was the very reason I had rebuilt the carburetor a year or so
ago. Anyway, I bought a rebuild kit which included a new valve and
valve seat. One thing I did confirm was that the problem wasn't
temperature related. The engine was dead cold when it started coughing
this time. Previously it hadn't occurred for a while. Actually, I
think the problem had just gotten worse.
The next day I pulled the top cover off of the carb so that I could
install the new valve. When I removed the seat, I noticed a tiny amount
of crud in the passage between the inlet line and the fine mesh screen
at the bottom of the seat. There was even a small particle or two on
the screen itself. I decided to pull the inlet line loose so that I
could swab out this passage while I had access. The rest of the innards
looked clean.
Replacing the valve was simple because the carburetor didn't have to be
removed. I didn't even empty the float chamber. Everything was back
together in a few minutes. I figured there was enough fuel left in the
float chamber to not have to prime. I pumped the accelerator pedal a
few times and tried the starter. The engine caught right away, ran for
a second or two then sputtered to a stop. I repeated this operation
with similar results. It seemed to me that the engine had run long
enough for the chamber to be full so I gave it an extra long crank with
lots of pumping; utterly dead. Figuring I had put something together
wrong I lifted the hood for a look. Suspicion confirmed; there was
gasoline all over the top of the engine. Every depression in the intake
manifold was filled and the garage floor underneath the car was flowing.
I quickly pulled the air cleaner off only to discovered that I had
forgotten to reconnect the inlet line to the carburetor.
Feeling pretty stupid I grabbed a rag and started soaking up the pools
on top of the engine. When I'd finished that, I rolled the car outside
and hosed the floor down. Having a river of gasoline right next to the
hot water heater was very unnerving.
After dealing with this catastrophe I got back to the original problem.
With the inlet line connected and the carburetor primed, the engine
started on the first try. This time it ran MUCH better. For a while.
Then the sputtering, intermittent cutting in and out started again.
Someone asked for a better description of the problem but I'm not sure I
can give one. Sometimes the engine seems to completely die briefly,
other times it seems to continue to run but very poorly as if it was
only firing on one or two cylinders. Sometimes it does act like it's
flooded. I recall a Plymouth Barracuda I once owned sounding similar
when the choke stuck on. Sometimes the problem persists for a while,
other times it completely disappear for longish periods.
While I still have this nagging feeling that the problem is fuel supply
related I spotted something very fishy on the electrical side. When the
ignition key is turned off (even removed), the ignition waning lamp
glows dimly. When the key is in the on-position the lamp goes off. If
the key is rotated to the right the light comes on a bit before the
starter engages. The light is completely off in the accessories
position. I've never noticed this before but then I haven't driven the
car at night recently so I don't know how long this has been going on.
I meant to check this morning to see if the light was visible in full
daylight, but I forgot. I think it's just a faulty switch but it could
also be related to the running problem somehow. I should mention that
the alternator and voltage regulator appear to be functioning normally.
I do wish I had a wiring diagram so I could have looked the ignition
circuitry over to see if anything else could be causing this other than
a problem in the switch. I had a somewhat similar experience a few
weeks ago while the right front turn signal light was removed. This
caused the right indicator panel lamp to stay on continuously.
Re-attaching the light to the the fender (completing the ground path)
made the panel light go off. Since this only occurred when the the
ignition switch was on, it didn't necessarily seem incorrect, but I
would like to have had a schematic to figure out what was going on.
Apparently the particular incarnation of my car (Mark II 289 Cobra) fell
though the cracks at customer documentation time. The 289 chassis
manual included an electrical schematic (mysteriously missing from my
manual), but it was for the earlier Mark I. The Mark I had mostly Lucas
switches, a Lucas generator and control box (voltage regulator) and
Smiths gauges. By chassis number CSX2200 (mine's 2282), the Lucas
generator, regulator and switches were replaced by Ford equivalents and
the gauges were Stewart Warner. I do have a very fuzzy photo copy of
the Mark I schematic, but I've spotted things on it I don't think even
the Mark I had. I suspect it's a hashed over schematic for an AC Ace.
I also have a copy of the later 427 chassis manual which contains a
schematic. When I got it I had hoped it would be useful, but the 427
reverted back to Lucas switches and Smiths gauges, not to mention other
significant differences in the dash panel layout, so it wasn't of much
help.
I also have a 1965 Ford shop manual which may help with the basic
ignition circuitry, but I don't have the complete picture. Ultimately
I'll most likely have to go through the tedious routine of tracing out
all the wiring by hand. Unless, of course, someone out there has an
accurate diagram they would be willing to share.
The next step is to replace the ignition switch. I'm not sure where
I'll get one but I think it's a generic early to mid '60s Ford switch.
This may not fix the poor running problem but it has to be replaced
anyway. After that I guess I'll rebuild the carburetor with the kit I
bought. Maybe something else in the carburetor is causing the problem.
On the electrical side, I do have a spare starter solenoid. Once that's
replaced, everything in the ignition system will either be new or
replaced with the exception of the ballast resistor and the distributor.
The ballast resistor appears to be an integral part of the wiring
between the ignition switch and the coil. At least that's my best
guess. I'm not sure how much of a job that will be to replace.
If none of this works maybe I'll start on the pile of HiPo parts taking
up space in the corner of my garage.
Roland
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