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| | | | Joined: Mar 2010 Posts: 79 Wrench Fetcher | | Wrench Fetcher Joined: Mar 2010 Posts: 79 | Hi all,
I have a 235 engine in my 48 Loadmaster.I have a new fuel tank,lines,fuel pump,in-line filter, and rebuilt Rochester carb but the engine will only run if choke is about half way out. I have checked for vacuum leaks( hoses, lines etc...) and have found none.When on the road it acts like it is starving for gas and you have to keep the choke almost all the way out. I have not done anything with the vacuum advance as it is working I guess. I am at my wits end. I have invested a lot of time and money in this engine and really want it to run before I ask for "professional" help. Any ideas?
Thanks
JMH | | | | | Joined: Feb 2004 Posts: 29,742 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,742 | You've got a clogged fuel passage somewhere in your carburetor. I'd suggest doing a complwte teardown on the carb, and soak it in a commercial dip-type cleaner. Flush it out with VERY hot water, then use a high volume of high-pressure air to blow all the passages clear. One carburetion instructor at the Memphis Tennessee GM training center used to say "Put 55 gallons of air through every hole in the housing!" The cleaner softens the crud, and the air blows the passage clean. Both are absolutely essential to a good carburetor rebuild.
Jerry
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| | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | Did you have the intake manifold off the head? If so you may have cocked one of the intake alignment rings when installing so the manifold is not fitting up tight to the head.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Oct 2007 Posts: 388 Shop Shark | | Shop Shark Joined: Oct 2007 Posts: 388 | jmh
I had similar issue, couple of things I did was adjusted carbuerator float, make sure it is as per the recomended height and sometime it chokes the float needle. It has to move freely up and down so actually needle will not allow gas only when float bowl is full. In addition I had adjusted air screw. Secondly I redid my TDC with my distributor and seems like now truck idles without choke turned on. I still have somemore issues like vacuum not advancing and I have ordered new one for my truck.
Good luck
Ganesh
| | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | Most "rebuilt" carbs are not right. Check the float level like Smokey say's. Make sure the power valve piston goes up & down & knocks the ball off the seat. Look at the main jet & see what size it is. It is stamped on it but may take a magnifiing glass to see it, depending on your age. A 235 usually has 56-58. If it's smaller then that get a larger one or drill it out if you have number drills available. The model B carbs are easy to work on & work good once you get it right. You might try advanceing the spark a little. Make sure you have plenty of fuel coming from the pump & it's not water.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Mar 2010 Posts: 79 Wrench Fetcher | | Wrench Fetcher Joined: Mar 2010 Posts: 79 | Thanks guys for the input. I checked intake today with carb cleaner and no surprises.I also removed the vacuum advance lines and cleaned. I did find out the vacuum advance is not working so I shall order one tomorrow. I paid dearly for that new fuel pump but I may plate the engine and go with an electric pump. The engine seems to run steady with the electric pump. Any opinions or more trouble shooting ideas?
Thanks
JMH | | |
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