'70 SS Backfires

[ssmonte70]

Hi Club Members....my dad has a '70 SS that won't start for the past few days. He's changed the oil, points, plugs, wires, and cleaned the distributor cap. It turns over fine but will backfire...any thoughts on next steps? Maybe timing? Any help would be appreciated...Thank you

[Patrick Sheean]

Has he checked the timing and dwell?

[ssmonte70]

Not yet...I believe he is doing that tomorrow Patrick...thank you I will definitely let him know to be sure to do that...

[Sam (Bones)]

after making sure the point gap (dwell) plugs, wires (firing order) and it's getting gas, are all correct and it still won't start but still backfires

 

time to look at the timing chain

[overdrive]

Quote:

time to look at the timing chain

I agree. It's an easy check. If the distributor hasn't been removed or turned since it ran right, bring #1 piston to top dead center (TDC). It won't matter whether it's at the end of the compression stroke or the exhaust stroke. Now check the alignment of the rotor and the cap. The rotor should be pointed at the #1 or #6 plug wire on the cap, depending on which TDC position the crank is in.

Does the motor still have the original timing gear and chain set in it? I had a '71 350 that did and the nylon teeth on the cam gear deteriorated and broke off. The chain jumped a tooth or two.

Dan

[ssmonte70]

Thank you everyone....tomorrow my dad is going to look at the timing as I have a feeling that is the issue because everything else is checking out...Thanks again, best club ever!!!!