1997 Voyager Stalling after Running A While

Hello. I have a 1997 Plymouth Voyager SE with just under 300,000 lns. (yes, that's right!). Just recently it has started to stall out when I have been driving for a while or if I have run several errands, so the van has been started and stopped at several different locations. The first time it started was driving home and it stalled on the highway - no shaking or any noises - just stalled. Started after a couple of minutes. Stalled again, waited 10 minutes, then ran fine for a few days until it started doing it again. Stalled 3 times on my way home from work (32 kms.) - let it sit for about a minute and it started right up again with no problem (no cranking needed, etc.) But these past few times the engine starts to shake. Have sometimes smelled either oil or gas after shutting off the engine. Gas tank has been anywhere from low to full. Mechanics seem to think it's a sensor located under the under the steering column (a 4-5 hour job to get at!), they said they cleaned up a few points and added something to the oil and it ran just fine for about a week. Any ideas? Possibly a fuel pump? Or oxygen sensor? Thanks!

With a high mileage vehicle (what is "Ins."? Miles?), and not being able to see it, it's hard to say exactly what may be causing the stalling. I'm not sure what your mechanics did regarding "cleaning up a few points and added something to the oil". I'm also not aware of any "sensor located under the steering column" that could be part of a stalling problem. If there is a sensor problem of some kind, it may be detectable with a OBD II code scanner/reader. However, before getting into more complex, and usually more expensive repairs, start with simpler and cheaper possible causes. When was the last tune-up (i.e., changing of spark plugs, air filter, fuel filter, throttle body cleaning, O2 sensor/s change, etc.)? If you're in need of those things, I would take care of them first, then see what happens. It may be as simple as that.