72 Engine misfire

[Leo M.]

Looking for opinions. Have a recently acquired low miles 72 350 base engine car. Installed new plugs, points, condenser, distributor cap and repro dated plug wires. Car runs great until engine gets hot after running 5 miles or so. Engine starts missing and backfiring through the carb. Shut it down and let it cool and it runs well until it gets hot again. Thanks

[Patrick H.]

Re: 72 Engine misfire

What brand/type of points and distributor cap? How did it run before you replaced all of these items? And did you save them? Were any of the parts removed original to the car?

[Leo M.]

Re: 72 Engine misfire

Used Delco parts. None of the parts replaced were original to the car. I drove the car very little before I replaced the parts, it ran fine.

[Gene M.]

Re: 72 Engine misfire

Used Delco parts. None of the parts replaced were original to the car. I drove the car very little before I replaced the parts, it ran fine.

Leo,
It stands to reason that some new component/s installed are not up to par or point gap is off. Suggest recheck point gap and dwell. What plugs? Gapped at .035"? But my opinion is the new plug wires are NG.

[Timothy B.]

Re: 72 Engine misfire

If you drove the car very little did you drive it to get it good and hot. The reason I am saying that is because you condition sounds like a coil problem, just keep it in mind if all the other work checks out OK.

[Edward J.]

Re: 72 Engine misfire

Leo, check the wires as the plug into Dist cap. sometimes if not plugged all the way down into cap this can create a misfire.

[Patrick H.]

Re: 72 Engine misfire

If you drove the car very little did you drive it to get it good and hot. The reason I am saying that is because you condition sounds like a coil problem, just keep it in mind if all the other work checks out OK.

I had the same thought, but if it didn't happen before and happens now, you have to wonder about one of the replaced parts.

[Dave K.]

Re: 72 Engine misfire

I had a similar problem on my 65 327/365hp. The distributor lock down came loose and the mechanical timing went to 20 deg advanced vs the appropriate 8 deg BTDC. Set timing and now runs fine. When changing pts and cond. I always follow with timing check.Dave K.

[Leo M.]

Re: 72 Engine misfire

Thanks to all that responded - I appreciate the suggestions. As I stated in my initial thread the car started missing and backfiring through the carb after being driven about 5 miles. After it cooled it would run until it got hot again. I had not done anything with it until today. I tried to start the car and it ran very rough and stopped running almost immediately. I started with the basics and checked and gapped all the plugs (new AC R44T), put in a new set of AC Delco points and condenser, gapped the points at .019 and was unable to get the car to fire. Rotated the distributor a few degrees either way with no luck. Checked all wires and connections and installed a different coil and still not getting car to fire.