There could be any number of problems. I strongly suggest you get an OBD2 code reader that is compatible with VW (not all of them are) and extract the trouble codes. That will give you real information from the car itself. For all I know somebody could have peed in the gastank. If the codes come up for timing problems, I'd guess the timing belt slipped. The ignition timing would not change by itself any other way except for the cam to be wrong. Since you thought the alternator was bad, there must have been some electrical issue. It might lead to a better guess if there was detail about that- unless you only changed it to be doing something that wasn't too hard for you. Good luck and don't replace any parts that are still good. That just wastes money. Spend good money on an OBD2 code reader.

If it wants to run while you pump the gas, it sure sounds like a fuel line problem. You changed the filter but that fuel flow issue points back to that, for me.

Why didn't you mention the pump??????

Best guess, IAC valve.

My 97 Jetta starts and then dies and will stay running if I pump the gas pedal but dies when I put it into gear. I've replaced the fuel filter, alternator and all the plugs and wires. What could be wrong?