Sucking sound on accelaration

[Ministry of speed]

There seems to be a strange sucking sound coming from around the back of the engine bay on my 1999 VT. Ive had a look for leaks around the throttle body but can't see any. any1 got any ideas on what it might be?

 

[ecotec]

There seems to be a strange sucking sound coming from around the back of the engine bay on my 1999 VT. Ive had a look for leaks around the throttle body but can't see any. any1 got any ideas on what it might be?

Is the vacum hose loose at all - it will make a little bit of noise - but maily will cause the motor to run very rich and run like a hairy goat at low speed.

 

[VT-565]

have you done any mods to your airbox? pod filter? anything like that? will cause that sound upon acceleration...failing that, i would try the vacuum hoses like ecotec said

 

[EXCESSV]

this is great. i should make a living out of telling people this.
check the PURGE HOSE.

if you take off the engine cover its basically a rubber hose with 90degree bends on the ends. it runs from UNDER your throttle body to the PURGE VALVE at the back.
it is either loose or stuffed. its like $10 from holden and unless its slipped off its better to buy then to glue the ends back on. although i have glued the end bits on as a temporary fix while waiting for holden to get it in.

there is a few thread on this but the one where i have pics and all is here:

http://forums.justcommodores.com.au/showthread.php?p=157490#post157490

 

[ecotec]

have you done any mods to your airbox? pod filter? anything like that? will cause that sound upon acceleration...failing that, i would try the vacuum hoses like ecotec said

Hey EcotecMania - quick question - I saw 126.5rwkw - nice. I'm getting 128rwkw out of my ecotec - not sure if that is about right for some of the mods I've done - SS Inductions CAI, K&N, Hiclone, performance plugs and leads, pacemaker headers, redback 2'5inch, TBS chip - The day it was on the dyno was very hot though - so wondering whether that would account for some lost power - what do reckon?

 

[VT-565]

Hey EcotecMania - quick question - I saw 126.5rwkw - nice. I'm getting 128rwkw out of my ecotec - not sure if that is about right for some of the mods I've done - SS Inductions CAI, K&N, Hiclone, performance plugs and leads, pacemaker headers, redback 2'5inch, TBS chip - The day it was on the dyno was very hot though - so wondering whether that would account for some lost power - what do reckon?

Hi Ecotec,
128 is a nice number.....i will get some more power out of mine when i nut out a problem which is causing the AFR's to go all silly, which in turn is hurting the power somewhat....at first we thought it was the MAF meter, so i replaced that, which kept the AFR constant, but a point too high! there are no fault codes whatsoever and the scantool says all the sensors are working which leaves maybe the ECU. i am getting a replacement soon, so i will definitely let you guys know how it goes. i'll put a quick list of mods on mine: enclosed K&N pod filter(stock cold air intake), pacemakers, stock cat and a hurricane 2.5" cat back system, yellaterra 1.8 high ratio roller rockers all with the stock tune still and that power reading was taken in stinking hot weather too.....the weather has a fair effect on engine output on the dyno, even more so when you go for forced induction as anyone will tell you.....so, when my CRS charger kit shows up, with the replacement ecu and 9psi pulley i will let you know what sort of power i'm making......

 

[Trewman]

I had this problem when I put the stereo in my vt, I pushed out a hole gromit instead of cutting it big enough for the 4 gage wiring. So i fixed that and now mines fine