Ok, so I've aquired a 1990 VW Passat, no rust( major point in Maine ).
It has a few problems.
The fuel injection system is acting very strangely. it would seem as if the thottle body position sensor is malfunctioning. it runs very roughly, when you can get it to start. and will cut out if you move the throttle quickly.
When you turn the switch, and let the car try to start, it seems to flood.
I have yet to check the spark.
suggestions so far?
Oxygen sensor. Unplug it and see if the car runs. Replace sensor if the car runs much better.
Also check coolant temperature sensor. (resistance vs temp)
Have you done a tune up, esp the spark plug wires? Also check for vacuum leaks and bad electrical connections. Are all of the fuses good? A Bentley manual might help you check components at the ECM wiring plug.
later, dave
Is the problem more when the car has been sitting overnight and there is more dew or humidity? If so, spark coil pack would be guess #1. Wires another possibility.
Watch under the hood while it is dark and foggy, or whatever equivalent you can approach.
Two suggestions: Check the air boot for leaks - wiggle it while running. Disconnect the cold start injector electrical plug.
Both have happened to my 91.
Good luck
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