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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Hillbillydrums on August 20, 2014, 05:15:42 pm
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Hey there. My truck.was running fine, actually just dropped the motor in a few months ago. It's never been running perfect yet, it back fires, and I havent wired up the elec. Choke yet. So I assumed that was carb stuff.
Anyways, we left to go to Hot August Nights with my 72 c10, and I returned to it not firing up. It cranks, and then it seemed like a cylinder or two would fire, but wouldn't start. And then it always smoked a bit out the exhaust. They are at least 15year old mufflers and the truck was parked for those years. But now it smokes a lot when floored and cranking. Then it'll stop smoking, (still cranking) and then it'll go boom and a ton of.smoke comes out.
Any ideas? Plugs are brand.new, and all I've done to play with it is try my other old distributor.
Thanks in advance.
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Floored and Cranking, are you holding the gas down while trying to crank it? By still cranking you mean holding the key to the start position?
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Your definition of fine and mine are a little different. Since you installed it, it has always back fired ?
Have you gone through the basics yet like timing ?
Do you have any catalytic converters on the truck ?
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Are you sure your plug wires aren't crossed, distributor a cylinder off, or have a sloppy timing chain? Is it getting good fuel? Also GOOD fuel, not dirty/watery 87 octane or stale gas?
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Floored and Cranking, are you holding the gas down while trying to crank it? By still cranking you mean holding the key to the start position?
Floored- yes, held down. cranking as in holding the start.
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Your definition of fine and mine are a little different. Since you installed it, it has always back fired ?
Have you gone through the basics yet like timing ?
Do you have any catalytic converters on the truck ?
I pulled it from another truck. Ran very good in it. All I did was add a edelbrock 600cfm carb from my k5, (carbs good, k5 needs a clutch so its non op) And I think it has back fired a bit since i got it in. More or less when i play with the carb adjusments. Yes i timed it when it ran. I havent again since i just swapped distributors, but i did that after the problem. And no cats, Just summit racing headers i had welded up to the existing exhaust. with whatever cheesy mufflers are on there.
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Are you sure your plug wires aren't crossed, distributor a cylinder off, or have a sloppy timing chain? Is it getting good fuel? Also GOOD fuel, not dirty/watery 87 octane or stale gas?
Plug wires i re did when i swapped distributors. And the distributor couldnt have been off before i touched it anyways, it ran fine, then sat. Didnt change. And the fuel looks good, not yellow or smelly. It was low (1gal or so), so i added another 5 gals of new 87 to it.
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Verify your on TDC, verify that the distributor is pointed to #1 plug,
Check for Fuel and Spark.
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Ended up being ancient mufflers just plugged with like squirrel nesting. Who'd of guesed?