Stranded at the Museum

Crud. I drove Otamay and Jim in Kristan's car (thinking it needed some exercise - something I've been doing every few weeks for the past few years), to breakfast, and then parked it here at the museum for our walk. This morning, it worked perfectly, until we got in it to come home. Turn the key, it cranks, but nothing fires. With half a tank of gas, I'm thinking either the plugs aren't firing, or the injection system isn't getting pressure, but nothing looks out of whack under the hood. Speaking of whacking, I tried tapping under the fuel tank, to wake up a possibly balky fuel pump, but no joy. And of course I've got no experience troubleshooting this car. All my connector wiggling was unsuccessful. AAA says we'll be waiting 120 minutes for a tow home. Boo. — at Denver Museum of Nature and Science.

Update: The AAA guy arrived after only an hour. After hearing my quick description of the problem, it took him 20 seconds to get the car running. He said "try to start it" and slapped the bottom of the fuel tank, whereupon it burst into life. So, I'm guessing a sticky fuel pump or clogged filter. I had tapped all around the bottom of the fuel tank with a piece of PVC pipe, but didn't really know where to hit. He knew exactly where to hit, and how hard. We left it at the car repair place to be looked at. Even if it works now, it will surely fail again later.

Update: The car service place couldn't reproduce the problem. They're thinking a little 44K fuel injector cleaner (a solvent) and a new tank of gas might be the best solution. They said it will help clean the fuel pump, which may have accumulated some varnish from old gas.