my commodore hisses when i accelerate

[s_ikari2015]

they tend to get soft with the heat after a while and often drop off. I don't know why Holden didn't use a small hose clip to secure it, or even a better barb on the outlet of the throttle body so it's a snug fit.

 

[mrVT]

a cable tie will prevent it from coming off again!

 

[mickymodge4]

bucket head a small drop of super glue is what i use to keep it on will never come off again even under a backfire!!!!

 

[ratz26]

dumb question but losing ur purge hose does that equate to losing some power as well ?...ill be checking my purge hose today to i get the same hiss..but im also missing a little bit of power.
this seems to be a very chronic constant problem for the VT

 

[drew23]

purge hose causes hiss and big problems for dual fuel LPG

Hi

I don't know why I didn't look on the internet first!

VS Acclaim with hiss on acceleration. Really screws up lpg causing bangs in inlet, blowing apart the air box. Very rough idle on lpg.

As usual garage couldn't fix it, saying it was normal throttle body noise.

Problem was just purge pipe had come apart just under throttle body.

Thanks for info

 

[WhatNoMods]

Thanks for Help and Photos

Thanks EXCESSV for putting up the photos and solution to the problem. The photos were excellent and helped me locate the cause of this problem that I had only just noticed on my VT.

Taking off the engine cover it was obvious as the elbow was hanging in space. Using long nose pliers I picked up the pipe and replaced it over the 90 bend. Sucking noise on slight acceleration immediately gone.

Interestingly the sucking noise only occurred under slight acceleration. Under heavy acceleration and cruising, no unusual noise at all.

Big Thanks to all who share these hints and advice.

 

[RK5TAR]

Great advice guys! I wanted to ask, I don't think I have the same problem, however my VT (manual on LPG) has occasional hissing sort of sounds at certain times when I accelarate. When I bought the car, I was told it was the gas going through the lines. The noise comes from behind the dash/firewall area. It does sound like gas or something wooshing through the lines. But my last LPG car was a Ford and it didnt make this noise. Should I maybe be checking my purge hose too?

 

[Promotec]

God this forum and its members are fantastic, yesterday i was out and about in the commodore and stopped at lights
and it was idling a bit rough, as I slowly excelerated off I could hear a slight hissing noise under the bonnet, today it
it was the same so sat down and typed vaccum leak into the search of this forum and found this post about the purge
hose under the throttle body I took off the engine cover and there was my problem, fantastic a 2 minute fix, thanks guys

 

[Haydo]

Replace the plastic piece of $h!t with a $5 rubber hose from Repco ;-)

 

[Mattacious]

Wow, that fixed my problem.

I just purchased a VT 2000 Series II & was starting to panic when I noticed the hissing noise after driving home. I thought it was the transmission on it's way out but after Googling it I found this thread. My hose had come off the throttle body. I just put it back on with a cable tie as suggested, and no more hissing!

Also the car used to shake when it idled, now it's still, and I swear I get better millage & performance.