Revs drop when stopping at lights?

[whitessute]

Hi guys, I have been noticing this for a few weeks now, I have an auto VZ SS and when i slow down to stop at lights the revs drop from just over 500 where it usually idles to around 300 causing the car to shudder before going back up to 500 again. Anyone got any ideas what might be the problem, i havent had any work done on it lately so thare are no obvious reasons for it. Thanks Guys

[BT 57 WA]

could be build up on your tps, have you had it serviced lately?
have you got aircon or something like that on?
have you done any mods to your car or is it standard?

[whitessute]

Serviced about 5000kms ago, no the air conditioning and heating were off, only mods cat back done over 12 months ago and 2 hole mod, nothing in the last 6 months

[BT 57 WA]

does your car burn oil?
seems like you have build up on the tps to me

i had similar probs a few years back.

[whitessute]

does your car burn oil?

not that i know of, never had any oil probs before

seems like you have build up on the tps to me

tps? How do i check this?

[SupremeVT98]

What's a TPS guys? I had this with my VT commodore before too.

[WalksGTO]

What about the O2 sensors, could it be that... My idle was all over the place a while ago and was fixed with two new O2 sensors

[mce]

does your car burn oil?
seems like you have build up on the tps to me

i had similar probs a few years back.

i think you mean IAC not TPS


IAC = idle air control motor

TPS = throtle postion switch

[dvader8]

I had exactly the same problem and realise how frustrating it is. Holden could not fault anything as usual. Their Tech2 device claimed no error codes which eliminated the O2 sensors according to Holden. I realise yours is stock but I ended up going back to my tuner and with a few quick changes all was good again. I believe he increased the idle speed or something to that effect but I've been happy since.

[CLUB_819]

our vz one tonner(gen 3) was doing that all the time, when we got the cam put in, so our tuner put a 3mm hole through the TB butterfly, cause of the electronic TB it doesn't let air through or something. But works great now.

Cheers
Scotty

[wrexed03]

Dont think it has a TPS. VZ has an electronic throttle setup. Fly by wire bla bla bla...
Take it back to dealer and get them to check it out or a good tuner.

Regards