I have a 360 I built a few years ago for my 74 Duster 360. It has an older Hughes/Engle cam HE2430, newer style MP adj mechanical advance distributor and Edelbrock heads, intake and carb. It has served me well, but probably doesn't have much more than 10K miles total on it. Just an occasional back-n-forth to work and weekend cruiser. I recently started misfiring at idle. It seems pretty good above 1500-2000 rpm, although it might be missing occasionally there too. The misfires is getting worse with time. I have concentrated on the ignition system as I figured it was a plug, wire, cap, or phasing issue. I had the engine out a while ago replacing steering box, headers, torque converter, and an oil pan leak. When I put it back together a buddy talked me into re-lubing the cam with cam lube as it was out for quite some time. It was right after this the misfire started and as I said it has continually gotten worse.
I changed, plugs, cap, wires as I went to RobbMC's cap adapter I bought from him a few years back. In addition I changed from an older orange box to a factory style and my Blaster 2 coil to an Echlen factory replacement coil. I also check cam phasing, which was off, and adjusted it by modifying the cap adapter to line the reluctor, rotor and #1 spark plug terminal on the cap. I haven't changed the pickup coil which is still an option I guess. There appears to be no vacuum leaks, the plugs are a little dark, but not bad. I went through the carb and thoroughly cleaned it. I also took a close look at all the harness under the hood (it was replaced with a Year1 harness a few years ago) and dash to make sure there are good connections, etc. It still pulls hard when got on and revs freely.
I'm stumped and am worried that putting the cam lube on wasn't such a good idea. Thinking I might have lost a lobe on the camshaft. It makes no funny noises, internally.
Does anyone have any ideas? I'm open to suggestions. I will probably try the pickup coil this weekend and probably pull the valve covers to see if there are any issues with the adjusters and rockers (Crane Golds). That might lead me to a cam issue.
Thanks in advance for anyone's help!
Jim