One problem related to fuel injection has been reported for the 1998 Volkswagen Jetta. The most recently reported issues are listed below.
Engine lost power when outside temperature was high (greater than 95 degrees fahrenheit). On the first occurrence (July 30, 1999, in des plaines, IL) the car was towed to a vw dealer in mt. Prospect, IL, where they detected a faulty air-gas ratio and said.