VZ Idle Issue

[Drewmans Crewman]

Hi Guys

I have been reading all about Rough Idle issues with the VZ Alloytech 3.6 V6 and thought I would put solutions in one spot for Newbies like me.

I recently bought a Crewman to fix up from Newcastle and knew there would be some issues but am surprised at some of them in that they seem to be Common VZ and Holden issues. These issues have been around forever obviously but there doesn't seem to be definitive solutions and I thought that I would make a list of the ones I have found and tried and will try when i get a chance.

The Rough Idle issue seems to be very common and solutions offered by other forum users are

1. New Plugs. (Done, no good)
2. New Coils. (Done, no good)
3. New 02 Sensors. (next payday)
4. New ECU either new or second hand but either way will need reprogramming or Holden to do it approx $900 - $1200.
5. Take negative cable off battery to reset ECU Wait 5 minutes and reconnect battery then rev at 2500-3000 rpm for 5 mins and then drive for half an hour. (Done no good)
6. Disconnect battery turn headlights and turn ignition on to drain residual power and repeat step 5.(Done no good)
7. Disconnect battery and take Stereo out as stereo keeps memory settings for ECU. (will try this one when I get the stereo removal tool)
8. Take fuel pump fuse out and start car till it dies and repeat attempt to start three or four times to make sure all fuel is removed from engine. (Done no good)
9. Use higher octane fuel or at least not E10. (Will do for new tank)
10. Don't do short trips too often as the car thinks it is normal to drive with cold engine etc.
11. Put in a Hotter thermostat. (will do anyway as is usually first thing I do to new car)
12. Low Voltage problem with alternator checked and producing around 14v.
13. Fuel Injectors. (will get checked before ecu replacement)

As the vehicle has done 218k kms Im happy to replace lots of things but I don't want to pay for a new ECU when it might be a simple fix and recur after replacing the ECU because the ECU wasn't the cause just a symptom.

Instrument Cluster needles failing is another issue i have looked at and I have decided to send it off for repair in Perth for $150 plus postage of $28. I have heard of Holden charging some friends of mine $1800 to fix the issue and then have it go again 7 months later. They sold the car and wont buy Holden again which is probably fair enough. This Crewman is my third Holden and certainly wont be going back to Holden again as I have had Issues with all three. Out of the 35 cars i have owned (my wife's, my kids and mine) in 28 years of driving the three Holdens would have to be the worst I have owned. Even my 2008 VW Jetta with DSG is better.

Anyway if you have had good conclusion to the same issue please post a reply or note,

I'm not after what it might be as it will just clutter the thread as with previous threads I have found on here.

 

[Tonner Matt]

Don't take my post the wrong way. Just offering some advice that could save you some money.

You've listed 13 possible solutions to rectify a rough idle, but have missed 3 of the most basic:
1. Clean the throttle body
2. Clean the MAF...Mass Air Flow meter
3. Have the vehicle scanned for any stored DTC's...Diagnostic Trouble Codes. Commonly referred to as Fault Codes
Look at it like this:
If it costs you, say $50 to get your can scanned, and you find just 1 fault code that can pinpoint and resolve the issue, isn't that cheaper than fitting new coils, plugs, sensors and whatever else has been suggested by internet mechanics and not fixing the problem. (No offence to the real mechanics on the forum)
Throwing new parts at a car in hope that it fixes it's problems is just a waste of money. Money that could be better spent on other maintenance or mods for the car.

 

[DLFHUB666]

Agree with above. The 1st stop with moden cars in trying to ID problems should always be a scan tool, then if no faults codes you can strat changing parts out relavent to said problem.You dont have to take it to holden to have it scanned there are plenty of other places that can do it.

 

[1994vr]

Don't take my post the wrong way. Just offering some advice that could save you some money.

You've listed 13 possible solutions to rectify a rough idle, but have missed 3 of the most basic:
1. Clean the throttle body
2. Clean the MAF...Mass Air Flow meter
3. Have the vehicle scanned for any stored DTC's...Diagnostic Trouble Codes. Commonly referred to as Fault Codes
Look at it like this:
If it costs you, say $50 to get your can scanned, and you find just 1 fault code that can pinpoint and resolve the issue, isn't that cheaper than fitting new coils, plugs, sensors and whatever else has been suggested by internet mechanics and not fixing the problem. (No offence to the real mechanics on the forum)
Throwing new parts at a car in hope that it fixes it's problems is just a waste of money. Money that could be better spent on other maintenance or mods for the car.

yep this is pretty much correct. Try cleaning or replacing your injectors also. Look at your fuel filter. sometimes they are so clogged the engine barley gets enough fuel. Do you have fresh fuel in the tank. anything older than a few months is not ideal. also check your idle speed is not low. there is usually a potentiometer on the ECU that adjusts the idle speed. im not sure if a VZ has that though. IF there is there will be a small adjustment screw that will be labeled idle speed.

 

[Tonner Matt]

Good call 1994vr. Fuel filter didn't even cross my mind at the time.
At least it will be a hell of a lot easier to change the fuel filter since his crewman is a trayback and not fitted with the tub.
At the risk of contradicting myself about throwing parts at a car, I suggest you replace the fuel pump at the same time as replacing the fuel filter, considering what is required to replace the fuel filter anyway. You don't want to be going through the whole process again in a couple of months if an issue arises, and at 218,000km's on the odometer I would class this as preventative maintenance.

Just in case people didn't know:
The Crewman and 1 Tonner fuel filters are in the fuel tank and the fuel pump module assembly needs to be dismantled to replace them.

 

[gungazza]

also have to remove tray there is a video in youtube to do this

 

[gungazza]

also bye a elm327 scanner on ebay

 

[greenacc]

Agree with what Matt said, start with the old school basics before you spend a cent.
CHECK and clean everything that opens and closes or can be removed with a simple screwdriver- and ensure they are clear of leaves, plastic bags, tight, and actually there in the first place.
Air intake,Air filter, intake pipe, MAF, throttle body, plenum if you can access, oil level and oil colour, under oil filler cap, coolant levels and colour, battery age and clean, vacuum hoses, exhaust condition, Oil or manifold leaks. Electric plugs and earths.
When that's done you'll have a better idea what's going on and can start digging deeper, and spending $$$!

 

[Drewmans Crewman]

yep already done and scan shows no faults. cheers

 

[Tonner Matt]

yep already done and scan shows no faults. cheers

That sucks big time when that happens. I'd do as 1994vr suggested because you've already fitted new plugs & coils.
Change the fuel filter and get the injectors serviced & tested.