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| | | | Joined: May 2008 Posts: 49 Wrench Fetcher | | Wrench Fetcher Joined: May 2008 Posts: 49 | My 55 2nd currently has a 1972 vintage 350 with a Quadrajet. The problem is that after the truck sits for a week, it is hard to start. It seems that I have to grind the starter until the fuel pump refills the carb. After that it cranks right up with no problems. My quadrajet knowledge is very limited, but is this a common problem and can it be easily fixed? The engine has unknown miles on it and smokes, so I am looking at a replacement sometime in the future. I do not wish to buy a replacement carb right now. Any suggestions?
Thanks,
Hugh | | | | | Joined: Feb 2004 Posts: 29,746 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,746 | There is a fuel filter with a 1-way check valve in it that's supposed to prevent fuel drain-back, but you've probably got the classic leaky float chamber that was common on a lot of QuadraJet carbs. It requires a teardown and rebuild, but a coat of epoxy similar to J-B Weld applied to the bottom of the float bowl where some drilled passages are plugged will eliminate the leak. Find a tech who knows what he's doing for the rebuild, as the average Quad has 23 consecutive adjustments to make on reassembly, and most of them are very critical to proper operation.
Jerry
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| | | | | Joined: Jul 2007 Posts: 461 Shop Shark | | Shop Shark Joined: Jul 2007 Posts: 461 | | | | | | Joined: May 2008 Posts: 49 Wrench Fetcher | | Wrench Fetcher Joined: May 2008 Posts: 49 | Thanks for the quick reply. I guess that I will just add that to the list of stuff to be done.
Hugh
| | | | | Joined: Nov 2002 Posts: 2,763 Carburetion specialist | | Carburetion specialist Joined: Nov 2002 Posts: 2,763 | More than likely, you simply have evaporating fuel.
As Jerry mentioned, there is a fuel filter with a check valve that prevents fuel from draining from the carburetor back to the tank on carburetors equiped with the windowed fuel valve. However, if your engine starts easily during the day after you started it in the morning, this is NOT your issue.
The well-known leaky well plug issue in the early Q-Jets (1965~1968) was corrected by Rochester in 1968. The 1968 and newer carbs do not have this issue.
Again, probably evaporation due to the modern fuel. An electric pump (at the tank) is the ONLY solution (other than remove the aircleaner and pour a couple of tablespoons of fuel down the carburetor prior to starting after the vehicle has been not started for a few days).
Jon.
Good carburetion is fuelish hot airThe most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes!The Carburetor Shop | | |
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