rough idling/running

[Rossbx]

I had problems similar to what you are experiencing now with my VP V6. I changed Plugs, leads, DFI module and coil packs. It seemed a little better after that but then it started again about a week later. It turned out to be the MAP and MAT sensors causing the problem. Try pulling the lead off the MAP sensor and see if it makes a difference. It is mounted on the left side of the firewall (on the VP anyway)
MAT sensor I think is on the air intake tube near the air cleaner. If you pull the connectors off them and it makes no difference, then that could just be your problem. I hope this helps

 

[Zuicider]

also wet relays

 

[subieboy]

Thanks guys

I had been thinking one or both Airflow sensors could be the issue laletly (we own a Subaru GTB - loves eating AFM's), so dunno why I hadn't thought of it before

also wet relays

Do you mean as in the relays in the bay (by the overflow tank)?

 

[subieboy]

So I stuck a Multimeter on both the AFM and the sensor in the airbox, after pulling the afm lead and it didn't change the idle or running.

The airbox sensor reading: 1242 ohm (disconnected), back probed with engine running I got a similar reading.

AFM reading (three prongs top to bottom as it sits in the engine bay). With the leads attached as per below:

• 1 "-" lead
• 2 "+" lead = 720 Ohms
• 3

• 1
• 2 "-" lead
• 3 "+" lead = 1757 Ohms

• 1 "-" lead
• 2
• 3 "+" lead = No reading

I then reversed the process from above (i.e. I changed the "+" and "-" round)

• 1 "+" lead
• 2
• 3 "-" lead = 720 Ohms

• 1 "+" lead
• 2 "-" lead = No reading
• 3

• 1
• 2 "+" lead
• 3 "-" lead = No reading

So am I correct to assume that the AFM is dead? Got similar results (cant remember readings tho) back probing the prongs both with the motor running and not running.

 

[Cheap6]

For the AFM:

You should have battery voltage at the terminal for the pink/blue wire at the AFM.

The brown/white wire is a 5V reference.

The third terminal will have a frequency output that increases with the airflow rate, switching the 5V reference to earth.

This may help some too:

http://www.memcals.com/pdf/VSV6 Auto Wiring Diagram.pdf

 

[subieboy]

thanks mate!

 

[subieboy]

So we checked the ignition system...

I decided not to do some of the following suggested methods for obvious reasons:
Spray water on the spark plug leads with engine running
Pull spark plugs off the coils with engine running
Pull injector leads/reattach injector leads while engine running

Luke me local friendly Holden dealer tech - nearly sh@t himself when I mentioned those above BTW

So we did the first thing that is apparently quite common with the VS, pulled the centre coil off, and changed it. One look was enough for Luke to be sure it was dead...

2 min later, new coil, no problems...

AFM readings are a bit dodgy but nothing to worry about at this stage.

 

[bigmicky22]

vs

hi just wondering if you have found the problem with your car yet? my vs wagon seems to be having the same problem but only seems to do it in (auto) 4th gear sitting on or above 80 klms p/h

 

[subieboy]

hi just wondering if you have found the problem with your car yet? my vs wagon seems to be having the same problem but only seems to do it in (auto) 4th gear sitting on or above 80 klms p/h

Yep,

It was the middle ignition coil that was bung, just replaced it and she was all good.