I have a 1990 that idles rough. I've changes plugs, wires, rotor and cap. I have a vacuum gauge installed in my car and it runs about 17 at idle. I have installed a K&N Filter and I had trouble making it fit perfect. Also, the flame trap lines are not snug. Can these cause a vacuum leak? If not, what is next?
My engine light is not on but it is idling rough. Oh yes, I have the VX cam, can that make a rough idle? Please help. My mechanic wants to adjust the valves, will this help? Thanks for the input.
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1990 240- 230K- IPD cam, springs, bilstiens, 3''exhaust, euro lamps

Check the intake snorkel (between AMM and throttle body). Pull it off and look carefully at the underside for splits... had 2 fail on me.

I've got the VX cam on my '92, and on startup there's a bit of a lope when she's running a little rich, but it does not idle rough at all. If your valve clearances are way out - more than just a few thou - that might cause a problem, but that's way down on the list of suspects.

After you've checked for vacuum leaks, perhaps do a throttle body cleaning (advice I need to heed one of these days!).

Loose flame trap hoses will cause vacuum loss. As will split vacuum hoses and air intake hoses, a loose manifold gasket, etc.

Vacuum hoses like to fail in places you can't see. Most vacuum hoses are cheap: I change them every couple of years on general principles. It *ALWAYS* has a noticeable, positive effect.

-_ Bruce
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-- Bruce / '82 244 (315k miles!), '86 745, '87 760Ti, '94 854