1997 VW Jetta GLX fails to start sporadically



About three weeks ago my '97 VW Jetta GLX (V6, 92k miles) failed to start one evening, with no prior warning signs. (The battery is a year old and the car cranks when it starts, so it isn’t the battery.)

The day after it started fine, though the “check engine” light stayed on - first time that’s ever happened. I took it to a local garage and their computer diagnostic indicated a problem with the crank sensor, cam sensor, and RPM sensor. All three sensors were dirty and loose, so they cleaned and reattached them. Car starts fine; “check engine” light no longer comes on.

A few days later, after some 10-12 OK starts, it failed to start again. I waited 15 minutes and it started fine - but this time, no “check engine” light. Took it back to same garage and this time they replaced all spark plugs, spark plug wiring (all were old and needed replacing anyway), fuel pump, and air filter. Starts great and runs noticably smoother than before.

One day later: my car dies in the middle of traffic. This is a first. Coast to side of road and waited 20 minutes - no start. Cranks but no ignition. Come back several hours later and car starts fine, but “check engine” light comes on again. Take it back to same garage, for third attempt.

This garage (which has a very good reputation) has no clue what’s wrong, and neither does my VW dealer, though I’m sure they’d love to charge me $2000 for exploratory surgery. Anyone have any ideas?