One problem related to fuel injection has been reported for the 1999 Volkswagen Jetta. The most recently reported issues are listed below.
This is not an isolated problem. The relay 109 has been brought to vw's attention several times. They have issued a tech tip on their website to dealers. My dealer replaced the wrong part and charged me for it. Now I have to wait for them to test it before they refund my money. This happened to me several times on the highway, in traffic. When you are stalled in the middle lane on a road and you see cars coming you hope they see you and don't run through the back of you. This is a serious problem and vw is ignoring it. In regards to the fuel injection, they are going through these too. The tdi engine is getting clogged (they don't kow why) and cause the fuel injector to fail. My dealership has had mine for a week. Part is on back order. Vw is not responsive.