stevenebm

iTrader: (6)

whats it meant to be at when idle?mines is reading -5ish then heading up to 0.i cant for the life of me remember what its meant to do.sit at 0 etc.does this sound about right?

749steve

iTrader: (1)

if its on mfi then the engine is at a vacum on idle and low revs so that is fine

tasos77

iTrader: (4)

mine in idle reading -0.8 bar

vroooom ptssssh

mine at idle used to read -9psi.

cossieboj

mine to!

stevenebm

iTrader: (6)

cool guys thats fine.just checking as its the first its ran on mfi for 8 months.the charge carrier seemed very hot tho,maybe just being paranoid tho.

jodyhoare

i thought it was ment to be -10 psi there or there abouts?

stevenebm

iTrader: (6)

i havent got a clue mate.why would it be sitting at 5 instead of ten?

Tim

iTrader: (1)

depends on cam etc

jodyhoare

it also depends on what kinda revs your sitting at on idle, does the vacum also depend on what boost your running?

jonny s2

iTrader: (12)

im sure mine ran -15,cant quite remember as its been that long off road for a revamp

Karlos G

iTrader: (4)

Yeah mine is between -15 and -20, it does flap around a bit though. As Tim said it also depends on your cam, port work, etc..
If your not pulling much vacuum at idle (950rpm approx) then it could be a sign of piston rings wear, just like a compression test would be low for the same reason.

Chris69

mines about -20 and lower when just coasting- glad to hear mines not the only one that flaps about a bit!

xr2wishy

iTrader: (2)

seems a bit low, should be around -20mm/HG
you don't measure vacuum in psi, only in mm of mercury

JamboRS

depends on several things where the needle sits as stated above
mines sat at 15

xr2wishy

iTrader: (2)

very true, a healthy amount of vacuum though, on a cold start it tends to be more(?)

Karlos G

iTrader: (4)

lol yeah i'm not sure why the vacuum is erratic at idle?
But yes mine also drops to about -25hg when coasting.

Probably because the idle is a little higher on a cold start, if anything it would pull less vacuum cold because nothing in the engine has expanded and nothing is seating/sealing (rings, valves, etc..) as well as it will when warm.

dan-dan

iTrader: (1)

Mine vacums to anywhere between -15 to -20 and lower on overrun, if you didnt have much vacum could it be a sign of a leak after the flap?

Karlos G

iTrader: (4)

Which flap mate, metering unit?

jodyhoare

flap? lol is that a technical term?

Herbo747

yeah mine sits between -15 and -20 somehwere around that general region.

dan-dan

iTrader: (1)

sorry by flap i mean throttle butterfly thingy