Barely firing...71

[Budduncan]

I have a mechanic working on my 71 and am having some ignition problems. Did the 71s use a ballast resister? I am thinking they did and the wiring schematics I have are difficult to read in my Owners Service Manual. I am thinking someone drew up better PDF schematics but cannot recall where to find or purchase them. The points seem ok, but we are thinking maybe a bad coil. The car ran fine cold, but after a few miles would start missing and now is missing all the time and will not really run. At least troubleshooting is easier when it is not functioning correctly. Any suggestions are welcome. Thanks,
Bud

[majicwrench]

"Mechanic" should be able to deal with this on his own. But, if car runs well cold, my gut would tell me points OK. These old cars plug idle jet CONSTANTLY making them run horrible. When it is running, cup your hand over carb and see if it improves.
WHy are you thinking bad coil?? Coils rarely fail, but everybody loves changing them. Did you test it, or are you just guessing??
Really need more info to help you out much.
Keith

[So Cal Mark]

your "mechanic" can easily test the entire ignition system with a scope. He can tell if the coil output is correct or any other defects within a couple of minutes

[bobplyler]

Coils rarely fail, but everybody loves changing them.

But... it's so easy to change them.

[Budduncan]

I agree with all comments; mostly more information is needed. I did not see any reply or comment on the ballast resister. My manual shows a resister integral with the distributer, but my 71 Spider indeed has a separate one on the negative side of the coil. I assume, since no one has ever changed it to my knowledge (we have owned the car since 1972) that it indeed belongs in the circuit. I would appreciate a confirmation on that. Again, thanks for your collective comments.
Bud

[vandor]

Yes, they had a ballast resistor mounted on the coil bracket in front of the coil.

The wiring diagrams are located at: http://www.artigue.com

[fiat218]

Yes, they had a ballast resistor mounted on the coil bracket in front of the coil.

The wiring diagrams are located at: http://www.artigue.com

That site don't work

[Budduncan]

Thanks, all. A new voltage regulator, and resetting dwell has my 71 running nicely again. Always something, but a sunny day and the top down brings smiles to everyone.
Bud

[narfire]

Try this for 69-73 electrical diagrams.. Again so many thanks to Brad for having these available to us..

http://www.corujoxx.com/MIWEB3/clubfiat ... 9_1973.pdf