VZ 6.0LTR miss @ idle

[mattie304]

Guys needed a little bit of help with this one.....
For the last couple of week my VZ 6.oltr has started to get a miss only at idle (800 to 900 rpm) notice able in gear with air on but goes away about 1200 rpm...
So far changed plugs (as fells like a lazy plug) and leads , cleaned the MAF.. no exhaust leaks before 02"s.... Any help would be greatly appreciated......Matt

[swingtan]

Cleaned the throttle body?

Checked for air leaks?

Reset the ECM?

I'd be doing these before anything else. Also, did this start occurring after filling up with fuel?

Simon.

[VYSS381]

A Mates LS1 had a miss at idle, it ended up being a valve spring after he changed coils and all chasing it. Wether it was a one off tho..

[mattie304]

Simon,
thank mate will clean the throttle body tomorrow and reset ECM....Hope fully this works
Oh it didnt start after filling up been doing it now for about 4500kms

[swingtan]

Oh, well in that case, all the early 6L motors have a bit of a rough idle that is just like a miss.

I'd also try running a couple of tanks of E10 through it with some fuel system cleaner.

[super coach]

how do you reset the ECM?

[VNV8]

FWIW I have a similar problem with mine, doesnt actively miss but has a shake at idle, only when coming down from speed (e.g 80kmh zone then stop at lights), I've had a mechanic look at it and they're thinking O2 sensors, because on the livedata they are jumping around and not giving the ECU a stable signal. Havent tried replacing them yet but might be something to look for.

[mattie304]

Guys,
I've still had not luck in finding the problem but in saying this it has not gotten any worst!

It feels like a slight misfire-ring plug and surges under light load to about 2 grand then you dont feel it. It does not run hot but looks like it blown a hose before i got it. ( not using coolant as far as can tell)
So far ive done plugs,leads, changed the injectors, fuel filter and the 4 o2 sensors.
Should i compression test?? Whats the next move.....

[mattie304]

Problem found( was thinking it was this, but was hoping it wasn't) HEAD GASKETS........changed coolant today and found the bubbles when bleeding..
Who has a good name for work around Newcastle?