Diagnosis help
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8th Gear
Joined: Dec 2006
Posts: 8
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Diagnosis help
1970 454 -LS5 -stock. I did a complete tune-up and carb. rebuild. Hard to start, rough idle until well warmed-up. I changed the mechanical springs from stock to medium (the light didn't work), adjusted the initial, vacuum and mechanical to have all in at 36*. I have to be very light on the gas until it hits 1,500 rpm, after that its a rocket. Seems everything works at its best between 1500 and 5500 but anything less then 1500 is very poor. If I mess with the timing (retard the initial), I can't get it going without pumping the gas at a red light. Additional symtoms: smells like its running very rich, seems to run much hotter, if it sits for more then an hour the fuel bowl runs very low or dry. I have to turn the engine over to pump fuel in the line/bowl. Am I running it to advanced? I've tried everything but I know I screwed something up in the process.
Thank you all
Baitweller in Miami, fla
Thank you all
Baitweller in Miami, fla
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
1970 454 -LS5 -stock. I did a complete tune-up and carb. rebuild. Hard to start, rough idle until well warmed-up. I changed the mechanical springs from stock to medium (the light didn't work), adjusted the initial, vacuum and mechanical to have all in at 36*. I have to be very light on the gas until it hits 1,500 rpm, after that its a rocket. Seems everything works at its best between 1500 and 5500 but anything less then 1500 is very poor. If I mess with the timing (retard the initial), I can't get it going without pumping the gas at a red light. Additional symtoms: smells like its running very rich, seems to run much hotter, if it sits for more then an hour the fuel bowl runs very low or dry. I have to turn the engine over to pump fuel in the line/bowl. Am I running it to advanced? I've tried everything but I know I screwed something up in the process.
Thank you all
Baitweller in Miami, fla
Thank you all
Baitweller in Miami, fla
with timing if you are using the stock distributer chances are you will need to get a recurve kit.
you did mention that you worked with the vacuum, mechanical etc to get 36 degrees.
you should get 36 degrees with the vacuum advance unplugged from the distributer.
as far as the carb run back,
NAPA has a fuel filter that replaces the oem one that has an anti drainback valve. lars posted the part # once for it.
Last edited by baxsom; Jul 22, 2009 at 03:25 PM.
