Saturday morning the car just would not start. Because of the periodic hard-starting I had lately been experiencing (except on the first crank in the mornings, when it fired right up) I'd already planned to swap out my distributor soon with one that I'd obtained from a friend that had very little mileage on it. This was the first time I've done it, and I had previously read the FAQ about it and was aware about marking everything and being careful replacing plug wires, etc. Replaced it (took about 15 minutes though to figure out how to get the distributor away from the firewall to remove it completely (had to turn the dissy upside, remove the plug that fits the Hall Sensor and wiggle it out). Replaced with good used one. Bolted everything back up and turn the key and it fires right up. Great (I think). Because I was a bit anxious I had my foot on the accelerator when I cranked it, and sat there a few moments gloating at my success. Then I took my foot off of the accelerator on purpose, and the tach bounces from 1000, then 800, then to 400, then it sputters and cuts out. I say, "OK, different distributor, maybe I need to slightly advance it" and I try that. No difference. I say, OK, what next ...? The car drove and pulled fine on my initial testdrive, but now if it sits at idle for over 15 seconds it goes 1000, 800, 400 sputters once and cuts off. Any ideas?