Car is a 1994 940 with Regina ignition system, distributor located at front of engine.

I was near the end of a 350-mile day trip from Virginia to Western Pennsylvania, a mile and a half from my destination, when as I accelerated to speed from a light--going perhaps 35-40 mph--the check engine light came on and the engine began to run roughly and have no power. I pulled over to see whether I could get it to smooth out again, but it did not, so I shut it off and looked for any obvious problems. Everything appeared normal. When I tried to restart it, it started briefly and stopped again. The more times I tried it, the less it ran until finally it wouldn't fire at all. That would suggest a fuel problem--like running out of gas--but the gauge indicates 1/3 tank of gas and we can hear it slosh when we shake the car. Gas was a fresh fill up two days ago.

Weather here is below or near freezing, colder than at my starting point, but car had been running well all day before this happened.

Tried cranking it with some starting fluid to see if it would fire, but it would not.

Pulled a spark plug, cranked engine and saw spark, but not a nice blue one, more of a yellow color.

Plugs, cap and rotor looked worn (are at least 30,000 miles old) so I replaced them. I was unable to obtain a set of plug wires today.

Symptoms suggest to me a sensor or relay problem, something electronic. I particularly note the fact the car did not simply stop running but ran rough first. The fact that it restarted briefly before failing to start altogether suggests a fuel problem. However, that it would not fire on starting fluid suggests ignition.

I've been reading through the FAQs and posts and found several likely causes. This post is to see if anyone recognizes the specific sequence of events and can suggest what caused it.

Anyone familiar with this exact sequence of symptoms?