97 jetta rough idle

i have a 97 jetta trek 2.0 standard. i was having problems with a no start, i changed the plugs from bosch+4 to the silvers and now when it starts it idles rough and sounds like its going to stall untill it warms up. i checked the gap and its correct...any suggestions?

check your distributor cap and rotor

spray water on the coil (if it arcs or stalls replace)

i checked the coil and it was fine. what i did find was the cam position sensor was faulty.

I changed the cam sensor, car ran good for a week now right back where I was. I towed it back to the dealer at their expense they scaned it and it came up as the cam sensor again and the engine speed sensor so they decided to change the cam sensor harness. I think I'm getting the run around. anyway It cranks and almost turns over. If I turn the key so lights come on I can hear a clicking noise and when I stop trying to turn it over ican hear a brief whine as if it was the starter. When it did start the last time it ran really rough(idling and bogged down on acceleration) untill it warmed up. any thoughts?:banghead:

my first thought to this whole problem was the vacume lines, are they all the origonal fiber/rubber lines? if so then you might want to replace them. my jetta had one rough idle until i checked those lines and found several breaks and a faulty check valve. replaced it all for about 30 dollars and it runs like a dream. check all your gaskets, hoses, and the throttle. how long has it been since you looked at your oil pump or oil for that matter? you mentioned that it would run rough until it was warm. yeah the people at VW might say that they are professionals however i have had them miss stuff that was right out in the open and obviously wrong. check it over yourself. look at every square inch of your car and look for stuff that is wrong. chances are it is something really stupid. :wink:

I had the same problem with my 97 GLX, it was the vacumn lines. They are as good as the wiring. Which is also crap.

Save yourself time and money, find another mechanic, old school is the best. The dealers depend on "scans", a real mechanic will actually look and diagnose the problem. I have tried all 3 VW dealers in my area, and was ripped off at each one. Good Luck!

crank sensors DO go bad also

man i switched to +4s and had same problems, i don't think it was the plugs, i switched back and still had the same problems. i was thinking carbone deposits, and the symptoms grew worse when you got the new plugs.