Tuesday, January 19, 2010
Tuesday, January 12, 2010
New coil, better spark.
Driving Barney around, I've been trying to figure out why there's such a strong fuel smell at times; I've gone through the whole fuel system and ruled out leaks, from the carb to the tank. Also, I've noticed hard starting, even after just a day of not being driven - much harder starting than fuel bowl evaporation could account for. Starting often required a loooong 10-second crank (to prime the carb, I'd assumed), followed by a second crank during which the engine would catch, crank a little more, then fire. Starting idle wasn't too smooth, either.
After thinking about it a bit, I started to focus on the coil. It's one of the few parts of the electrical system I hadn't touched. Looking at it, I found that it was a very old Delco-Remy. Was it OE? Who knows? At the very least, it wore two coats of black paint; one original and one from the engine bay repaint. There was rust showing on the case, and some corrosion in the tower. So I decided to replace it.
NAPA shows Echlin #IC12 as the OEM application for a '63 Lark, so I footed it down to my local store and picked one up last night. At lunch I went out and replaced the old Delco, and when I turned the key -- presto! Barney fired right up. This is noteworthy because my last drive was on Saturday, 3 days ago - plenty long enough for fuel to evaporate from the bowl and cause a hard-start condition if that's what the trouble was.
But with only one pump of the go pedal to set the choke, the engine caught with a healthy roar after only 3 turns of the crank, and ran smoothly at fast idle, just like it ought to. I think that the old coil, while still operative, was probably not putting out enough spark to economically run the engine, a problem the new coil solved.
Goes to show how sensitive gas engines are to good spark output, I guess.