Erratic tickover

[578HSV]

Monaro 2005 CV8. Last couple of weeks the tick over is becoming erratic, sometimes stalling altogether. Anyone else had this ?

If so what was the cure ?

Cheers

Gaz

[vxr2010]

mine was 02 sensors

[578HSV]

Cheers, are the sensors Monaro specific or generic GM parts do you know ?

Gaz

[vxr2010]

don’t use rock auto , order from australia , the rock auto ones were still causing issues , i think they are quite car specific , the auz ones were from
[e-mail] , they worked very well , also clean maf first , check battery voltage plus no air leaks plus do you have any fault codes , but mine was an 02 sensor issues , it was not showing any 02 sensor faults on a code reader of the dash , until it got worse dash started showing an issue on start up but no codes stored , when it was put on a proper code reader it came up with 02 issue

[maccavvy]

get it diagnosed 1st in case codes are showing .

check intake pipe for splits. the plastic ones are prone to It

clean throttle body

maybe faulty idle control valve. clean that too

[SturdyHSV]

I'd be very surprised if the O2 sensors weren't just generic, why would GM reinvent the wheel for such an arbitrary part?

If you can be bothered, you could feasibly get under the car and unplug all 4 (might be a bit awkward to get to connectors etc.), if the car then idles OK then you've got your answer.

The car should be able to idle fine in open loop, as this is what it does upon warm-up anyway. Likewise you could unplug the MAF and it'll still run (yes you'll get lots of engine lights).

I would also be surprised if O2 sensors (that would just feedback rich / lean) could stall the engine, maximum short term adjustment is 15% fuelling, if it's been way off for ages I believe it's then a maximum of 10% in addition from the long term fuel trims.

This is from memory admittedly, I haven't looked at the tuning side of things for a good 5 years

I'm also fairly sure you can leave the battery off for a while which will reset the long term fuel trims, so if it is fuelling that's going off by enough to stall the car that'd buy you back 40% of the adjustment.

Personally for it to stall I'd be looking at the 'air' part of the fuel / air / spark mix.

[vxr2010]

i bought two sets of 02 sensors from rock auto as they are a cheap option , the sensors were not their cheapest , neither of them worked , i bought from au issue solved

[mfp4073]

I bought two o2 sensors from AAS in Newcastle, they are genuine AC Delco parts and work fine. I didn't replace the rear down stream sensors.
The only reason I replaced them was because I had fitted new headers and cats at the time.
I think I may have the original sensors somewhere, if you want to make a trip up to Teesside you can try them out before spending any money.

[fred bloggs]

vxr2010 said:

i bought two sets of 02 sensors from rock auto as they are a cheap option , the sensors were not their cheapest , neither of them worked , i bought from au issue solved

I bought some non original ones, they didn't work. I just have none now. Mapped them out.

First guess is split vacuum hose, check all those, then get it scanned.

[Drihump Trolomite]

Don't clean the maf to test, disconnect it. Does it fix problems? If so then clean it or better still replace it.

Maf wont trigger a cel but o2 failing will. Whatever you do, once it's fixed get your trims reset

[Drihump Trolomite]

The sensors are generic but you need to get the right generic ones.