Wretched 504 Stranded Me Today But Now Running Fine

My mates back home warned me about buying an American spec., ’70′s issue Peugeot but I was determined to show everyone that with a little determination and ingenuity an old diesel Pug could be used as a daily driver and excellent conversation piece. As I write this I can see the repulsive rust pail in my driveway, laughing at me, daring me to open the bonnet and spend another long night tightening leaking fuel and hydraulic lines and tracing blackened wires. I worked on the beast all weekend trying to sort out the hard starting that has suddenly plagued the 504 and this morning she roared to life on the first twist of the key — no ether needed! Sad to say approximately five miles from my home the beast went silent at a traffic light and refused to restart despite fiddling, ether, massive amounts of cursing, etc. A couple of blokes helped me push her to the roadside and as I sat inside awaiting the tow truck I thought I would try one — more — time —– and the engine came to life with a huge puff of gray smoke out the exhaust and sat, clatter-clattering away as if nothing had happened. What do I do now? Do I attempt to diagnose the problem, drive it until it breaks or (my preferred option), drink myself into a stupor? A little advice, please?