TheeVOoNE

iTrader: (1)

I was wondering if this is normal with turbo cars. Bascially the vaccum fluctuates up and down on idle, it is like it is vibrating. The range is tiny but it fluctuates on a steady pace. All lines are tight and this is on my DEfi BF series boost gauge. Anyone have this or info on this?
TIA

Bom's Evo

iTrader: (14)

whats ur rpm @idle? is it fluctuating as well?

kevo

iTrader: (7)

I think its normal, Mine does that sometime, especially when the motor is cold, it fluctuates in .5 psi range between 18-17 in vac. My car is completely stock. spike to 20psi tapper to 17 and hold all the way to redline. I wouldn't worry about it.

YEVOVIII

I have the same gauges also. At idle my needle move up and down just a tiny bit. Seems normal.

XRS-Lift

autometer boost guage here. Vacuum bounces within .5 psi at idle as well. Its normal.

1QWKEVO

iTrader: (3)

slight fluctuation is normal... at idle on a cold motor it should be slightly different than that of a warm motor... A warm motor should see at most 1 PSI fluctuation... Don't worry if their is a vacume leek you will either see the vacume loss or hear the leek. Normal leeks can see an excess of 5-8 psi of loss if not more... depends on the size of the leek

TaiwanEvo

iTrader: (1)

do you have any mods.. Usually with my bov and my intake.. i notice more of a difference

eclipsegs2k1

why does it vaccum at idle?? I've been wondering this for awhile. I know that this is a stupid noob question, and I have done a search and didn't really find the answer, so any help would be appreciated

juyanith

iTrader: (7)

Well, I'm no automotive engineer but I would guess the gauge measures vacuum at idle because the engine is "sucking" in air. Under boost it measures pressure because the turbo is forcing air into the system.

simevo

iTrader: (1)

I have the Greddy gauge. It came with a Orifice to help prevent idle fluctuations.

simevo

iTrader: (1)

Greedy Gauge