Hi to all. New to the site. Heres some background. Needed a vehicle & did a widow friend a favor by taking her late husband's '74(thats the year on the reg.) that he'd been working on before passing. Was told he'd rebuilt the 460(which I came to find out is from a '71) and bored it out 30 over. Got it started and it ran so-so. Put new plugs, wires, cap and roter, as well as vacuum advance in and then timed. Started having issues with dieseling, backfiring and intermittent loss of power. Sometimes even dying while driving, as well as difficulty starting. Noticed that would sometimes not start while turning over but would fire as I let off the key. Checked spark and saw same thing happening. I think I've narrowed it down to either the electronic ignition('74 first year for that I believe),or the coil. Any help would be greatly appreciated.

 

Have you put a vacuum gauge on it? Have you checked all the vacuum lines?

I'd post pictures of your set up with the air cleaner off.

 

Next step check and verify the timing before throwing any more parts at it.

 

sounds like the electronic pickup in the dist

 

I don't have a wiring diagram in front of me. However, I believe there is a circuit that runs from the starter solenoid to coil to maintain 12v power while cranking.

 

I used to carry a spare module in my 75 F250, 79 F150, and 86 F250. Saved me many walks home. Found that the 3 connector car module would work in my 2 connector truck . At least until I got the right module.

 

2 small terminals on solenoid , one marked "S" the other marked "I" which goes to the coil

 

"I" for ignition this only has power when the starter is cranking.
"S" is for start put power (12volts) to it and the starter will crank the motor over.
Dave - - - -

 

It's possible that there is more than one shortfall involved.
Don't "assume" that new means good when dealing with parts. Try to verify individual component performance whenever possible.
If you've narrowed it to the electronic ignition or coil, that means that the carburetor and engine possibilities have been eliminated from consideration.
The 1974 460 should have an electronic ignition. The modules have been infamous for causing starting/running problems, but that doesn't mean that that's the problem. If that & the coil are the only possibilities left then it might be O.K. to buy these and do a replacement. Even if you're wrong about it being one of them, it would be good to always carry a spare for each of them. They are not costly.

 

It might be the ignition switch too. Some continuity tests would find out for sure.