Mopar Action On-line – Tech Questions


Tech Question

Maris Cherup, Newark OH, 1973 Plymouth Duster 340

I have a 1973 Duster 340, original motor, it has startedmissing. I have tuned it up: basic plugs wires, rotor, and cap. Noimprovement, so now I have pulled all plug wires one at a time and when ipulled #6 cyl off with motor running it didn’t die down so it makes mebelieve I have problem with the valve train?

I have checked push rods they are straight if anyone can give me someinput as to what it might be it will be greatly appreciated – could it be abad valve spring ? Valves look to be going up and down ok but looks I guesscan be deciving? It only pops out that side of exhaust too

The motor only has 69k on it, but 30 yrs old i know…

…and keep the mopars rolling!

Sure sounds like valve problem (not necessarily valve TRAIN, could beburned, bent, etc.) Could be a holed piston, too! Does it crank:”ruh-ruh-ruh-ruh-raaaah-ruh…” like one hole has no compreesion?

But, you gotta do either a leakdown test (best) or a compression test.Anything else, and you’re just throwing parts at it like a Chevy mechanic!



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