Could be clogged sock or broken pickup tube.

What happens if you just run a hose from the fuel pump to a gas can
(temporarily?)  If it runs well, time to siphon the tank dry and start
over, ASSuming that the fuel line isn't pinched or rusted through
between the tank and the engine (a distinct possibility.)

You could even run a hose into the pass. compartment and set a 5-gallon
can on the floor for a test run to see how it works under load (NOTE:
this is dangerous, use precautions, carry an extinguisher, and try at
your own risk)

IIRC a '73 uses a return line off the fuel pump, so you'd actually need
two hoses to make this work properly.

The best upgrade you could possibly do to this truck is to add a HEI
distributor from a later (but not too late, you want one from a
non-computer vehicle) HEI so you don't ever have to mess with points
again.  Also be aware that there are a very few weirdnesses with a '73,
as it was the first year of that body style... the headlight switch is
one, I believe the knob/shaft is different than later years.  Not sure
of all the others, but there are some.

good luck,

nate

(whose dad has a '73 Stepside that became just such a project while I
was in high school, it's now his baby...  also bought another '73 as a
parts vehicle for a '49 Chev street rod project, so I have some
experience with these.)

Also, have you cleaned or replaced the sintered bronze filter element in
the inlet to the carb?  My dad ended up tearing down the original engine
in his own '73 (a factory 2bbl/307, FWIW) because he didn't know about
the filter in the carb inlet...  D'OH!

nate

(in my defense, I was maybe 5 years old at the time and had never heard
of a sintered bronze filter element, much less knew that Rochester used
them.  I soon learned about them however, along with a few words that
previously I had no idea were part of the English language!)

based on what others have said, here's my 2 cents on troubleshooting it:

Before starting it, take off the air cleaner and pump the gas - do you
get a squirt of gas in the carb?  If not, you've got the problem my race
car had where the gas was all gone after it sat for a while - either
leaked from the carb into the intake or somehow "backflowed" back into
the tank.  (we ended up upgrading the tank, the fuel line, the fuel
pump, and the carb anyway so I never did figure out what was wrong.)

to eliminate the fuel tank, run the truck off a rubber line going into a
jerry can in the bed and go for a quick spin.  Obviously you need to
make sure it's properly secured. :)
Better = plugged tank pickup or fuel line

You might want to plumb in a fuel pressure gauge - I believe 5-7 psi is
normal for a QJet.

Last but not least, the choke works properly, right?  If it's stuck on
or not coming on at all it'll be hard to start and will stall.  It
doesn't sound like you've taken it for a test drive after it's had a
chance to warm up.

You could also pull a plug and have a look after it dies - are they
soaked in gas?  Maybe it's not lack of fuel, maybe it's an ignition
problem?  Have you checked the timing?  Does it backfire through the
carb or exhaust?  What happens if you ease into the throttle vs standing
on it?

Ray

Ok, I'm going to throw this one out there!! Is it possible that your
gasline to the fuel pump is conneted to the return line instead of the
pickup line from the tank...with only an 1/8 tank it might have run for
awhile like that till the level reached a curtain point, The return
line from the pump was use to return unused gas back to the tank.

You sure could be describing a pinhole leak on the suction side of the
fuel pump.  A small leak will suck air into the line and empty it when
it sits so it is a bugger to cold start.  As it gets worse it can air
lock the line.

Depending on where the leak is, all you might see is a stain on the
metal line where it clamps to the frame rail or a stain on a small crack
in one of the rubber lines at the end of the steel tube.  Lots of times
these suction leaks don't drip on the ground.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
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