I just bought a 74 Camaro and it's back firing horible when it's idled up. I've been told; "timing,s-plugs, wires, points, and it needs ahigh rise intake since it has a new 650 edelbrock on it". I'm going through the electrical side of things. It has new alternator, plug wires, points, plugs, & distributor cap. I drove it back home from San Diago CA to St. Louis, MO. I had to tweak the timing to make it through the mountins in Vail/Denver. Any ideas?
I have seen the hold down foot of the distributor get corroded so the distributor loses it's ground which causes strange firing something like you describe.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06did you check the compression on all cylinders? if all cylinders are low its the timing chain.
Really?!?! Can't be the cam?!?! Can't be the valve adjustment?!?! Can't be the lifters?!?! Can't be push rods?!?! Can't be the rings?!?!? Can't be the rockers?!?! Can't be the rocker balls?!?! Can't be the rocker studs?!?! (stock ones push out of the heads) Can't be the bore?!?! Can't be...
there are some clues there that the timing chain has jumped. its a
1974 so its old maybe by now the timing chain is stretched and it has even jumped a cog. he had to adjust the timing to get through the mountains. If the valves are not opening and closing in sync with with the pistons going up and down it may or may not help to adjust the timing. i think the confirming test is to check the compression. if they are even and low the timing chain has jumped. if some are good then its not the timing chain. It takes all day to replace the timing chain (and of course you will also replace the gears) so you want to make sure before you tear it apart.If the engine backfires, the timing is off. If the spark timing is okay, the valve timing is not. You've played with the spark timing, now it's time to check the valves.
Might be good first to pull the chain cover and make sure it's lined up nicely. I might want to do a compression test before anything else, though. I _hope_ you did a compression test before buying, though.
--scott
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