VS Ecotec rough idle

[primo]

DFI pull it off and clean all the contacts, checking coil resistance doesn't really mean anything, when under load is a different ballgame, was the oil seperator under the pcv put back in correctly with the hole facing into the manifold? Smoke could be burning coolant from a leaky intake manifold gasket, very common on these engines.

I actually didn't pull out the oil separator just the PCV valve and spring was taken out and cleaned.
I have changed the intake manifold gaskets..........the white smoke under hard load has been there for a couple of years.

Thanks for the purge solenoid pics.

 

[The1]

does it use much oil?

 

[primo]

does it use much oil?

no it doesn't................although I have noticed oil in the exhaust (back garage wall) after starting starting.

 

[primo]

Update

Thought I'd post an update on my rough idle. I seem to have fixed it by replacing the Air temp sensor and cleaning the MAF with proper MAF cleaner. I also earthed the o2 sensors at the ECU(D14, D16 & A2) as proposed in another thread to treat poor fuel economy.

So after replacing the IAC, fuel pressure regulator, o2 sensors, fuel pump/filter, coolant temp sensor/ sender, CAS(both), leads and cleaned the injectors, plenum and intake manifold..........it seems in the end it was the ATS that may have been causing the rough idle......although I wasn't receiving any errors pointing me in the right direction.

Just before I replaced the ATS this week, I took it for a compression check(when the idle was at it worst, thinking the rough idle could be bottom end or head issues. All six cylinders reported a reading over 150 with only 5% difference between cylinders........so compression all good.

Three different mechanics looked at the rough idle and none could locate or fix the problem :-(

 

[nathanVY]

Well done man, can you post more details on the ATS?

 

[The1]

Lots of sensors to cause issues these days without a logging device or scantool it won't be obvious sometimes

 

[primo]

Well done man, can you post more details on the ATS?

Well i checked the resistance of the ATS
At both the unit itself and at the connector
And all seemed fine, but as soon as replaced
It with a genuine ATS, the idling started to behave straight away.

I also earthed the o2 wires properly at the Ecu at the
Same time but not sure that would of
Contributed to fixing up a rough idle given
The o2 sensors are new from Holden?

Additionally, cleaning the MAF with proper
Cleaner also made a noticeable difference after replacing
The ATS.....actuall i highly revommend it but
Use proper MAF cleaner.......you Would be suprised
How much dirty film comes iff. It's been 3 days now and it's
still behaving.

It's been a costly exercise replacing every sensor
With genuine, but in the end the car now runs ultra smooth.
Still has some smoke when going hard(rings by the looks of
It) but for general driving it's great.

 

[pomiedore vs]

Hi primo,
Just a quick twist regarding o2 sensor earths.
I know the post you refered to and it seems to work.
However, there is a reason why you should not earth the o2 sensors to the chassis.
In short the ECU will get a false reading because of interference from auxiliary devices.
Eg: demister, interior fan, radio, amp, etc.
O2 sensors generate tiny voltage signals which can be easily disturbed by bad earths or wiring or anything with a coil.
By earthing at the ECU and joining terminals d16,A2,D14 you are just hiding the real problem.
Also the ECU will not be able to tell the difference between RH bank and the LH bank when trimming the fuel mixture.
This can result in alot of frustration in diagnosing future problems as certain error codes will not be accurate.
I think it was your ATS / MAF giving you the bad idle.

 

[primo]

Hi primo,
Just a quick twist regarding o2 sensor earths.
I know the post you refered to and it seems to work.
However, there is a reason why you should not earth the o2 sensors to the chassis.
In short the ECU will get a false reading because of interference from auxiliary devices.
Eg: demister, interior fan, radio, amp, etc.
O2 sensors generate tiny voltage signals which can be easily disturbed by bad earths or wiring or anything with a coil.
By earthing at the ECU and joining terminals d16,A2,D14 you are just hiding the real problem.
Also the ECU will not be able to tell the difference between RH bank and the LH bank when trimming the fuel mixture.
This can result in alot of frustration in diagnosing future problems as certain error codes will not be accurate.
I think it was your ATS / MAF giving you the bad idle.

I was under the impression (from another post regarding o2s) that the VS o2 sensors share the same earth with the heater and that has been prone to giving incorrect signals to the ECU ?

The main reason why I wanted to provide a separate earth at the ECU is bad fuel economy and not so much the bad idle, as I have had poor fuel economy for years prior to the bad idle(only manage around 300ks on a full tank). All the usual components related to bad fuel economy has already been changed, ie, o2 sensors, fuel pump/filter, plugs/leads, fuel pressure regulator, temp sensors, ATS, professionally cleaned the injectors, checked the purge hoses from the tank to the canister to the TB, stripped and cleaned the intake manifold, plenum, TB and MAF and finally checked the cylinder compression.

I haven't been able to measure the economy since replacing all these parts as my odometer and speedo shat itself recently, taking it to St George instruments tommorrow to repair. If all the above hasn't seen a marked improvement in the fuel economy then I am stumped.

 

[thripplebuttix]

Rough Idle HELP!

Hi, I'm experienceing I think the same Issue you had.
It idles rough and surges, its a 6 cylinder auto. Ofter I place in Nuetral at the lights and this helps.
I've had mechanice look at it, stuffed gallons of injector cleaner into it, leads, filters, plugs. haven't had injectors cleaned.
Engine makes a breathing swoosh noise for thirty seconds when it starts up, (This is a new thing) motor has 190000klms, owned since new and always serviced.
New Engine Mounts.

What and where is the ATS?

Thanks, GB