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| | | | Joined: Jun 2009 Posts: 331 Shop Shark | | Shop Shark Joined: Jun 2009 Posts: 331 | Hi guys,
This question is due to my lack of experience, but that's how i learn...by asking you guys!
My 283 usually runs great, idles evenly, sounds like it's running as it should if I drive at lower rpms (ok, aside from the clunks and noisy lifters associated with a 50 year old engine) If I take it on the highway, as i often do, it has to rev high, and if I get off the highway after twenty minutes or so, it sounds alot different, it "chugs" and has considerably less power. Almost sounds like it's running off time or missing a cylinder. If I give it literally only two minutes of driving on lower rpms, it goes back to normal. Any thoughts?
ps, the engine is mostly original to my knowledge, except for the air cleaner and oil pan. It uses no oil, which leads me to believe someone rebuilt the heads once. It still has the points distributer. | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy Adam61, is there any smoke associated with the poor running after the high speed run? | | | | | Joined: Jun 2009 Posts: 331 Shop Shark | | Shop Shark Joined: Jun 2009 Posts: 331 | Nope, no smoke that I know of...a bit tough to tell because the exhaust pipes end before the rear axle, but I never notice anything in the rear view. | | | | | Joined: Jul 2008 Posts: 326 'Bolter | | 'Bolter Joined: Jul 2008 Posts: 326 | Adam;
"chugging" like running out of gas? I would look at the fuel filter and/or maybe a weak fuel pump. "chugging" like running with the choke on? I would look to the carb float level or maybe the fuel pressure from the pump. Either way it sounds fuel related. Next time jump out and look at the exhaust as the other poster suggested, it maybe rich. Good luck.
SimS | | | | | Joined: Apr 2005 Posts: 187 Shop Shark | | Shop Shark Joined: Apr 2005 Posts: 187 | Sounds like a lifter problem.If they are hydraulic lifters,they could be floating at high speed.If they are original they are probably wore out.
_____________ Floyd If we choose being kind over being right,we will be right every time. Knowledge is a poor substitute for experience. Remember what is precious to another, may not be to you, but it is precious nonetheless. 1948 Chevy 2-Ton | | | | | Joined: Apr 2005 Posts: 1,971 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 1,971 | Get the choke off as soon as possible after starting. Using it too long will foul the spark plugs. Make sure the choke opens fully when you look into the carb. Readjust if necessary. | | | | | Joined: Feb 2004 Posts: 29,743 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,743 | The float level in the carburetor is probably a little too high. When you transition from cruise RPM to street driving, the fuel in the float bowl is spilling over into the venturi and creating a temporary rich-running condition until the level stabilizes. Drop the float down about 1/16" or so, and the problem should go away.
Jerry
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