Greetings.
The car is a 1992 Buick Park Avenue, base model. It has a lovely 173,000 miles on it and I am not the first owner. About a month and half ago, I was driving along the road and the engine died. No hesistation or stalling, it simply cut off and a few of the dash lights flipped on (red LED for battery, check engine, maybe another). I got the car off the road, turned everything off, and restarted the engine. It ran fine after that.
About a week or so later, it did it again, but this time it stuttered a bit first when I was applying gas and then cut off. A month goes by, nothing. Then, yesterday evening, the engine started to stutter as soon as I turned the car on. I left it alone and figured I'd check it out today. It ran fine this morning, but this afternoon did the old insta-die and shut down on me. Power is still present and there are no real surprising sounds - the engine simply dies and I coast down the road, praying I still have some pressure in my brake lines.
I ran a paper clip from A and B on the... switch thing... and got the code 42. Browsed through my Haynes, and it described the ECM as taking information from both the crankshaft sensor and the camshaft sensor and then sends instructions to the EST to set the proper spark timing.
So, how do I go about fixing this problem? It sounds like it still could be a variety of things - camshaft/crankshaft sensors, or the ECM, or the EST? If it's any help, the tachometer became "unreliable" a few months ago - it'll randomly jump up to 6000 or so RPM when I'm driving, and sometimes will show me an idle speed of 3000. The engine is, of course, not jumping around like that, but the tach seems to think so. The oil pressure gauge has just recently started to do the same thing.
Suggestions?