vacuum gauge readings
 

Just wondering what the differences mean betweeen vacuum readings.

My car is steady between 0.6 and 0.55 Bar. (8.6 psi - 8psi).

whats everyone else getting?

Bout that... -60Kpa on a std motor

is there a difference on vacuum between a ej205 207 and 257 ??

dont know about differences but my stock motor 06 reads between -50 / -60 kpa as well at cruise

not really, they should all be between ~50-60kPa...avcs on the later engines negates any larger cam diffrences in idle vac there may be, factory fitted cams/engines with emissions in mind ....

An engine with large after market cams and head/intake work etc may end up with less.... my engine with the largest cams JUN make suffers low vac at idle(~25Kpa)..but thats built for low(ish) compression and camed up hard...

bump this thread

iv developed a really rough idle (I dont see the revs fluctuate), but I see my vacuum flucuating from -0.6 to -0.3.

Driving on cruise, everything feels fine.

Is this another AFM problem? Or what else could it be?

Could it be a slight vaccum leak at all? Not enough to stall the engine but enough to create improper fueling or something?

how do you pressurize the lines to check/hear/gauge leaks ?

I have found the best way to find a leak is to spray each hose with contact cleaner and wait till you find one that affects the idle. Contact cleaner is usually best as it does not leave any residue.

See how that goes, or you can use any petroleum base, flammable product until you locate the cause.