ENGINE IDLE SPEED

[CSUVY]

We have had our Monaro CV8 (06 plate) since January, we are very pleased with it and have had no problems apart from ~ sometimes it seems reluctant to idle at 800 rpm and keeps rising up to 1200 rpm. The rev seems slow to drop to idle speed when you lift off the accelerator. Our local Vauxhall garage checked the throttle bodies when it was recently serviced but could not find anything wrong. Has anyone else had this problem, and if so any suggestions? Thank you in advance, Craig

[Doleboy]

You tuned or stock?

[V8 EOL - Rich]

Mine does that if you are moving. When you come to a stop it goes down to 800 no problems. I think it is down to the tune (Wortec) but I could be wrong.

[CSUVY]

It's stock not tuned

[ringram]

Its likely a feature in the tune called throttle cracker. Which adds airflow to the engine when the car is moving, kind of helps smooth gear shifts and the driveline. It can be tuned out, but if you get it to fall too fast things can get a bit jerky and when loading it with steering lock near idle and aircond etc it may even stall. All a balancing act really. But stock tune is very conservative so you can probably speed it up without Ill effect if you dont go overboard.

[anonymous-user]

Don't suppose its the aircon kicking in and out is it - that will raise the revs and lower them as it turns on and off.

Sorry if that's a bit of a noddy suggestion!

[Doleboy]

CSUVY said:

It's stock not tuned

If you've had any other symptoms such as a couple of mpg less than usual, and a reduction in part throttle response it could be the o2 sensors.

Have you noticed the idle issue for a while or is it just the last tank of fuel?

[Monnington]

gsxr750steve said:

Don't suppose its the aircon kicking in and out is it - that will raise the revs and lower them as it turns on and off.

Sorry if that's a bit of a noddy suggestion!

Not at all, mine idles smoother with the AC off, it can also take a while to settle down sometimes, has got a remap though.

Can't say it bothers me though, most fuel injected vehicles seem a bit random in the idle department...

[anonymous-user]

I have the same car as you and it does the exact same thing, I have a wortec tune but I think it's always done it. Doesn't bother me that much.

[well_fans]

my 04 cv8 on startup after lying for a week or so will often take 30 secs or so to stabilise at around an 800rpm idle, it actually drops to 500 and rises back up to 800 repeatedly during that period.

[ringram]

Sounds like time to do some idle tweaking dude