Missing At Idle?

[UWAM]

I've just noticed my car is misfiring at idle. Every second or so I guess, I can feel it sitting in the car. Sounds fine, seems to drive fine, doesn't seem to do it on boost.

I think there's a vacuum leak somewhere, I can hear a hissing noise around the front of the plenum, could that cause it? Or is it normal? Idle speed is around 700 RPM. Doesn't really hunt for it either.

R34 GT-T. Stock standard.

Cheers

[blk94r33]

Yes, vacuum leak could cause it to miss intermittently at idle. How long has it been playing up? Number of things cause these problems, compression, blocked injector, fouled plugs etc. Get some aerostart and spray it around the area you can hear the hiss, but keep it away form your air intake, if the idle changes, suspect a vacuum leak.