Bobby,
remove fuel cap and peer into tank with a good strong explosion proof
flashlight. You should find Gas (Natch!) and if you peer around in there you
just might find a mechanics rag. I have seen it done when doing final prep
on a truck for inspection and you see the inspection party coming. I was
told it was the only place to dump the rag and not have it found and hurt
the inspection. Also look for the old standby SAND!! Honestly you would be
surprised what I've pulled out of fuel tanks when trouble shooting similar
problems like your experiencing. OK, Where are you?? Are you down South
where it's Hot?? Got to be. Carry a couple of plastic milk jugs filled with
water with (if you have kids swipe/borrow it from them) a supersoaker water
gun/toy. Drive the truck till it starts exhibiting the performance gripes
you wrote about and when it starts acting up pull over open hood and "shoot"
the carburetor/fuel line to the fuel pump if mechanical and try to drive
truck and see if it made a difference. If it makes a difference you are
expierinceing "Vapor Lock". The gas vaporizes as the carb/line becomes too
hot for the gas to remain in liquid form. Two ways to correct this are add
insulation to the fuel line to prevent it from getting too hot and the real
fix is replace the fuel pump with one that has a higher fuel pressure which
prevents vapor lock.
OH YEAH!!! ALMOST FERGOT!!!!! when it starts losing power pull over
shut engine off and go to fuel tank and lean over fuel fill with ear right
next to the fuel fill cap and turn the cap and if you hear air rushing in
CLEAN THE VENTED (?) CAP fuel tank vent. No air going inta da tank?? No or
very little fuel pumped out!!! Just a last minute thought. Now that I think
about it I'll bet thats it. Think about it......Full tank of fuel or near to
it drive short distance and vacuum in tank little or no fuel out to carb.
Half a tank or low fuel and would take 4 or 5 miles to create vacuum.
Remember a six pack of Pepsi on ice will make it more bearable when it
grumbles at ya.
Best of luck and please let us know what ya find.
Jim
James Shanks
The Line Below is my Ham Radio Callsign
n1vbn@bit-net.com
The line below is my Ham Radio Packet Address
N1VBN @ WB1DSW.NH.USA.NOAM
-----Original Message-----
From: pendleto@usit.net <pendleto@usit.net>
To: Military Vehicles Mailing List <mil-veh@mil-veh.org>
Date: Thursday, September 21, 2000 11:10 AM
Subject: [MV] M211 losing power
>Greetings,
> List, I need your help. My 1953 GMC M211 2 1/2 ton truck is losing power.
>It will run fine for a while, then it starts losing power. It may go four
or
>five miles before it start acting up, or it may start after a 1/2 mile.I
>have changed the coil (two news one) points, all three of the capacitors
and
>the plugs. I have changed fuel pump and the filters,checked the timing.
>any ides?
>
>Bobby Joe Pendleton II
>MVPA#17657
>
>
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>
This archive was generated by hypermail 2b29 : Tue Oct 24 2000 - 20:55:36 PDT