Yesterday as I was leaving the Kirkland Concours d'Elegance my car died. I started it up, drove out of the Porsche area (it's running great at this point), and about 30 seconds into the trip up the road it started popping and backfiring. It eventually got so bad it wouldn't even run, and died. I ran the battery down trying to restart it. That resulted in this embarrassing moment.
It's been doing this for a couple of weeks. It pops, backfires, loses power, and then seems to get over whatever is going on and runs fine. It only does this on a cold start...never when it's warmed up. It lasts for about a minute.
I charged the battery today and it started right up. I let it idle in the driveway until it started backfiring and checked the fuel pressure, it was a steady 3.5. I took it out for a run around the block and for about 30 seconds it ran bad - a minute later, it ran great.
Any ideas? It's hard to troubleshoot a problem that goes away in a minute. I know a minute doesn't sound like much, but on the road, it's endless. And now that it's stranded me, I gotta fix this. The car is a '66 with a 2.2T motor with Webers, an MSD ignition, and a sport muffler.