Ignition problems on Stock 71

[MyBronco15]

I got my 71 a couple years ago and slowly have been fixing what doesn't work.
Well, it never ran very strong but started easily, idle was smooth, responsive throttle as long as no load. Also wouldnt come to temp. So i cleaned and flushed coolant, added thermostat (po ran without with none) Advance timing to around 12 degrees. Ran much better until it got hot and bogged down. Pulled a couple plugs and they were black as coal so i Leaned out the Carb, ran again and felt much better but seems to be missing a lot, fishbites and fluctuating idle. Pulled plugs after running a bit and black is starting to burn off but still look almost new. cleaning those up now, checking gap and reinstalling but what should be done for ignition system? Plug wires did bite me a bit when i was tuning so was gonna replace those but seems like more. Also when I was setting timing was using vacuum and light but it didnt seem to work exactly like i expected. Engine would run rough around 4 btdc but never really ran rough the other direction. I maxed out where vacuum hit fuel line to carb. Any thoughts? Contemplating duraspark but still think this should be something simple. Should I just replace wires cap and rotor and see what happens even though they all look good?

 

[Justafordguy]

Does it still have points ign? If so I'd set/change out the points and replace the condenser.

 

[B RON CO]

Hi, as mentioned, do you know how old the points and condenser is? We used to change them every year, they burn out after about 15000 miles. Make sure to get a quality set or the new ones could be worse then the old ones. Many guys go to a Pertronix ignitor, and I would get their flamethrower coil as a set.
You should change the cap and rotor if they show any oxidized terminals.
You could start the Bronco at night and look for arcing plug wires, but if you don't know how old they are I would change them, then you know the whole ignition tune up is done.
The engine should run great with 10 to 12 degrees advance. Set the timing with the vacuum hose off and plugged. You can see if the vacuum advance is working by hooking the vacuum hose back up and give it some gas. The timing mark will move up under the water pump if the advance is working.
Check the firing order and make sure that is good.
If you can't set the timing because the distributor hits the thermostat the distributor is one tooth off.
Look closely for a vacuum leak.
The mixture screws only lean out the idle, and have no effect at higher RPMs.
Good luck

 

[MyBronco15]

Thanks for the input gents. It is points still and I have no idea of age but things look in good shape.

Plugs were gapped at about 44 which seems incorrect for points. Gapped to 30 base on old Post from broncobowser and made new set of wires and paid attention to routing from viperwolf post.

Tuned carb with new setup and then set timing and seemed to run perfectly at idle now. Will put under load hopefully tomorrow but think things are looking up. Would like to upgrade to duraspark soon but think I'm in a good place for now.