VZ Missing on Idle - New sparks and coild fitted.

[Stevee]

Try running a tank of Premium fuel through it .

Good advice after the fact that the coils were buggered.

I have a 2006 VZ - V6 wagon and got the coils replaced due to failure at 94k.

The car is running great (touch wood) and i put 98 octane in it, expensive, but would rather pay a bit more to keep engine running well.

Ive noticed since using 98 the engine and response is much smoother and seem to like it. Also fuel consumption is great, even stop start. Im getting on average 11 litres per 100, not all that great, but a lot better than i was before.

Ive even kept tabs on what i put in to what ive travelled. 50 litres gave me about 420 km with 25 litres left, that would increase to about another 200 - 250 km give or take. But i dont drive with my foot flat to the floor though.

 

[morphix]

Morphix If its a 05-07 alloytec engine thats done over 150000 kms its probably a stretched timing chain.Im in the process of installing one now.

It's a '04 and its now done 221,400km.. the issue showed up back when it was at 169,000km.

After changing the coil packs and then last weekend i pulled the spark plugs out to check compression (all 170psi) 1 spark plug was cracked, so i replaced it and used brake cleaner to clean all the spark plugs up the car runs amazing!

The car has so much more power without needing to push it and doesn't die in the ass up a hill.

There is still every now and then a blip in engine idle and i can see fuel trim readings are still a little off, i'm thinking it may just be the timing chain but it seems to cost way more than its worth.

If i didn't need my car for work, i would attempt to do it myself, but take time to do it and not rush.

Are you doing the chains yourself or someone else? And at what cost?

I also checked the fuel pressure which was showing around 402-403kpa, which seems to be the 'approx 410kpa' reading..

 

[st3r3otyp3]

Also clean your throttle body as the gunk can make it idle funny.

 

[roddy_257]

yea mate did the chains myself with the help of these forums and the Haynes manual:
Another timing chain diy - pics of step-by-step disassembly
check it out.If you tackle it now when its not so bad it may save you a bit on replacing the idler gears and crank shaft sprocket,my ones were too far gone so i replaced the whole lot.Also found a bit of sludge building up at the time.From what your explaining your symptoms seems very similar to mine.just about to finish the job tomorrow actually so hopefully all goes well.Look up Mace Engineering for the chains speak to Steve they are reasonably priced.

 

[morphix]

Depending on the cost, if i was going to tackle this i would replace other stuff thats either iffy or would need to replace in the short future anyway (to save having to do it again).

How much did you pay for the chains, etc? And what did you end up purchasing?

At the moment i don't have any cash to spare to be able to get this fixed either via a workshop (waaay too much) or myself, so would have to wait.

Thankfully if this is the issue, it is extremely minor at the moment.

 

[DaCoffee]

So did the rough idle go away cos it all sounds the same like mine. I've replaced coils and plugs but no improvements with rough idle at times like it builds up then does it then normal then rough. My timing on a scanner is up and down from 6 to 11.