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[kcl]

Seems to point to air leak on 2-4-6 bank causing weak mixture and knock sensor kicking in,could the servo or the pipework be leaking air

Airleak has been strongly considered, however:

All vacc hoses checked

Idle steady - would be increased, if air leak?

Airleak wouldn't affect it at high RPM, when it needs as much air as poss?

Or, could it be, a missing/damaged inlet trumpet seal? It would still idle ok but when giving it full throttle the engine sort of sucks extra air through the o-ring  :-/

[JamesV6CDX]

Seems to point to air leak on 2-4-6 bank causing weak mixture and knock sensor kicking in,could the servo or the pipework be leaking air

Airleak has been strongly considered, however:

All vacc hoses checked

Idle steady - would be increased, if air leak?

Airleak wouldn't affect it at high RPM, when it needs as much air as poss?

Or, could it be, a missing/damaged inlet trumpet seal? It would still idle ok but when giving it full throttle the engine sort of sucks extra air through the o-ring  :-/

Do you mean the plenum O ring?

[kcl]

Thats one possibility that the plenum o-rings leak but it should not have that effect... But what I meant is you had the trumpets off when doing the stat? So the red rings between inlet divider and trumpets might leak?  :-/

[Kevin Wood]

I should also point out that both lambda sensors are reading "rich" solidly on hard acceleration. That doesn't mean it's impossible for one cylinder to be  going lean, but I think it's unlikely...

I don't believe it could be an air leak. Anything that affects full throttle running will completely kill the idling, and it idles perfectly.

Ignition coil packs are handed, so doubt they could be swapped between banks.

I suppose we're assuming it's bank 2... and James' live data does show a few murmurs from bank 2 sensor, and nothing from bank 1. Hardly conclusive, though.

What we do know is that the live data is showing knock retard active, and it doesn't on my car, no matter what I do to it.

[Jimbob]

How were the MAF readings?

[Jimbob]

James, can you plug the "My Naff Code Reader" in, set it doing flight recorder data and go for a drive and email me the log.

[Kevin Wood]

How were the MAF readings?

MAF was reading as expected at idle. Fuel trims were not getting excessive at any point.

[Kevin Wood]

How were the MAF readings?

MAF was reading as expected at idle. Fuel trims were not getting excessive at any point.

Hmm. Could have swapped out the MAF with mine and eliminated it, though, I suppose. Just didn't seem to be pointing in that direction.

[Jimbob]

my theory is the MAF has been replaced in the past, with a cheap chinese ebay one, which often contain just a resistor! so am after some correlation that it really seems to be working as it should.

[JamesV6CDX]

hi Jimbob

Yep I am going to create another log tonight, and will email it to yourself and Kev.

Kev had visibility of my original one, which is what much of this is based on.

Reg the MAF - it looks to be a GM one, not a cheapie. 

[Big_Roger]

Hi,
I and I am sure many others can hardly wait for a good result from all this investigation, and hoping we never get this problem with our motors.

I don't know anything about knock detectors, only that they are "tuned" to pick up certain range of noise.

I just wondered if this knock sensor was picking up noise or vibration from a faulty bearing on the water pump or air con compressor or steering pump??

Just a thought.

Roger

[JamesV6CDX]

Took the 3.2 out to play tonight, armed with laptop, monitored by SWMBO.

Have noticed that "knock control" becomes "active" at the slightest touch of the throttle.

Eg, if I rev the engine on the drive, stood still, about 3000 rpm it goes active.

When driving, ANY load on the engine turns "knock control" "active". Constantly.

The strange thing is, I tried unplugging both sensors in turn, and then together - and even with both unplugged, it still shows knock control as active, under those conditions.

The only time it's ever "inactive" is when not touching the gas, eg downhill, on the overrun.

Really confused.

The drive (with both sensors connected) was "sprited" to say the least (you'll be pleased to know it was to Cheltenham, Kev, to get your LPG cable!)

And I have the excel log of both the drive with the sensors connected, and then a short drive without them connected.

I'm not sure how to post them on here, though - probably need some hosting which I can't access on this silly connection

Help, please? 

[TheBoy]

Did the other side show similar when unplugged?

[JamesV6CDX]

Did the other side show similar when unplugged?

Knock control seems to be a global thing, rather than for individual sensors?

Think examination of the logs is required 

[Jimbob]

mail me the logs, ill host em