I picked up a 440 U code '70 Challenger. Was restored something like 15 years, had about 37 miles put on it over the last 10. The car was a "reference" restoration back in the day, with a powertrain by Frank Badalson, etc. Totally stock, even uses the solenoids on the carter carb and the points distributor. The coil is stock. Everything is showroom stock. Really nice car.

Anyway, I had a few things to fix (water pump leaked, brake booster solidified, and so on) and have reached the test and tune phase. First driving session, ran really great, loads of power, just a few non-motor tweaks and some timing hit or miss adjustments. Second day, took it out again, ran really well until the problem started. The "lots of power" started to seem a little less, very subtle, seemed to be a slight miss in certain circumstances. Drove it some more and the slight miss became a very pronounced miss from the exhaust, not quite a backfire. I head back home with it and it stalls as I pull in to my side street. Starts right back up, goes down the street and stalls again as I pull in to my driveway, sort of missing the whole time. Get it started again, very easily, almost get to the garage where it stalls again, this time it won't start.

OK, new day, trying to figure what is wrong with it. Here is what I know...has a 1/2 tank of fresh gas (race and today's premium mixed). Plenty of gas shooting down the carb throat when the pedal is pressed. The easilycranks easily, no strange noises, Pulled a plug wire, checked with a spark tester to ground, no spark when cranking. Pulled the coil to distributor wire, no spark when trying to crank it, holding it near the exhaust manifold. In my pile of parts I had a coil and ballast and swapped both with no change. When the ignition key is in run position, the carb solenoid normally extends like it should, until now when it does not. The distributor solenoid is making a buzzing noise when the key is in run position, but I had an extra solenoid which got rid of the buzz but made no difference on the problem or the carb solenoid not extending all of the sudden. It did have the radio noise suppressor, I disconnected it in case it was a short.

So any ideas? I replaced then positive battery harness as I freshened up the car, the rest of the harness are as I got it. The engine harness seems to be not original, stock appearing, but sort of loosely wrapped which makes me wonder if someone had been in it. Everything under the dash is clean, unmolested, looks original. I have a Sun Distributor machine, before taking the car out I swapped cap, rotor, points and condenser, Dwell was a solid 30 degrees. Cap and rotor are NOS.