[Chrysler300] Fuel for thought and action

["Rich Barber" <c300@xxxxxxx>]

It is quite a mystery, probably with a multitude of solutions.  I decided to
make a few observations.  Our 1955 C-300 with 78,000 miles on it and a
couple of years on a fuel pump rebuild was parked in our garage Saturday
after driving home from a car show.  It has been hot in the garage since
then.  Both clear glass bowls were down to about 3/8" of clear gasoline,
down to the bottom of the ceramic filters.  Makes one wonder where the gas
in the bowls went???

I gave several pumps on the accelerator, closed both manual chokes (!) and
it fired on about 1/2 rotation and continued to run on idle--signifying
plenty of fuel in the carbs and enough in the .  Ten minutes later, both
bowls were still full, but I noticed several fuel leaks, including drips off
the bottom of the back bowl, at several points on the carbs and on the
relatively new diaphragm on the rebuilt fuel pump.

Too early for firm conclusions, but I'm thinking the porous ceramic filters
may be acting as wicks to lift the gas in those bowls up to a leaky gasket
surface and/or to the inlet line for a ride back to the tank--although how
the gasoline can get back through the check valves in the fuel pump, I
haven't figured out.

Anyway, thanks for triggering my curiosity.  I've discovered several
hazardous fuel leaks and the dino juice is running about $3.15/gallon here.

Others might try what I've just done.  Start and run a very short time so as
not to heat the engine.  Check for leaks.  Fix any found.

The laws of physics dictate that if a source of ignition is applied to a
flammable mixture of fuel and air, combustion WILL occur.  Adequate air is a
given and spark is highly likely (but must be timed properly--highly
advanced timing may prove harder to start) so the key is to get just the
right amount of fuel vapor into the cylinder with the air.  The standard way
of achieving a flammable mixture is to prime the intake manifold with a shot
of liquid fuel pumped from the bowl by the accelerator pump(s).  Like
anything else, this can be overdone by pumping so much raw fuel into the
intake that the air fuel mixture becomes to rich to support combustion
"flooded".

An easy check of the accelerator pumps is to pull the air cleaner(s) before
cranking a cold, stale engine and observe the carb throats while the
throttle rod is actuated to operate the accelerator pumps.  Healthy spurts
of fuel should be visible.  If not, there is either no fuel in the carb
bowl, the accelerator pump is shot or the system is plugged somewhere.
Teardown, cleaning and overhaul may be indicated.

I also happen to believe that the heat from 700 pounds of 180 degree cast
iron is more than enough to boil off a couple of ounces of volatile
gasoline.  It takes a very tightly sealed system of carburetors, filters,
pump and fittings to contain the volatile fuel at high temperatures.  As
noted, a high-mileage brass float valve will have hammered itself into its
seat and only act as impediment to flow, not a seal.  And, of course, the
float level must be set at its proper level to assure an adequate volume of
fuel in the carb bowl when the engine stops.

The last part of the system is the lines, fittings, connections and in-tank
filter/screen in the tank.  Leaks, restriction and plugging here is not
unknown and the gas cap must be vented.

I realize 99% of the readers of this gibberish know this stuff by heart, but
some may not have been lucky enough to work on these brutes in the days
before EFI or may have overlooked some obvious problem.  Since not all
Chrysler 300's are having this problem, the solution(s) probably lie in one
or more of the areas described above.

Best C-300'ly wishes for a quick start,
Rich Barber
Brentwood, CA
1955 C-300

-----Original Message-----
From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On
Behalf Of News4ge@xxxxxxx
Sent: Tuesday, July 18, 2006 5:17 PM
To: crossram@xxxxxxxxxxxxx; Chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] two questions

I hope there is an answer to this hard-starting problem.  It's pretty 
annoying.  If I start the K every day, it's fine.  If I let it sit for 2
days, it 
will sometimes start then stop.  This, I think, tells me that there's fuel
in the 
carb, but not in the line.  If it sits more than 2 days, it's cranksville 
until the battery almost runs down.  I've had 3 different fuel pumps in it,
3 
different single quad carbs ( 2 Carter rebuilt themoquads and a reman
Edelbrock) 
on an old Offy manifold, and the ram setup with 2 rebuilt 3505s.  None made
a 
difference.  I've been told that the modern fuels evaporate faster than they

used to, but it's hard to believe that's it.

There has to be a simple answer to this.  These cars didn't behave like this

when they were new.

I know that an electric fuel pump can solve this, but there's some concern 
over there being too much fuel pressure, and how to hook it up ( flow
through 
the existing pump or bypass it?).  Also, this should not be necessary to
make 
our cars run like new.

Any more ideas?  Thanks.

George Clineman


[Non-text portions of this message have been removed]




To send a message to this group, send an email to:
Chrysler300@xxxxxxxxxxxxxxx

For list server instructions, go to
http://www.chrysler300club.com/yahoolist/inst.htm

For archives go to http://www.forwardlook.net/300-archive/ 
Yahoo! Groups Links



 






To send a message to this group, send an email to:
Chrysler300@xxxxxxxxxxxxxxx

For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm

For archives go to http://www.forwardlook.net/300-archive/ 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/Chrysler300/

<*> To unsubscribe from this group, send an email to:
    Chrysler300-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/