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[05omegav6]

Essex Big Al iirc had a similar issue with the throttle motor... could have been someone else in Essex, but I do remember Albs being involved in trying to fix it

[Kevin Wood]

One possibility I can think of is that the throttle shaft is bent, meaning an imbalance in the air supply to the two banks at idle, but, now I think about it, I think that one's blown out of the water by the manifold multiram valve being open at idle, so that would balance the airflow anyway.

A big enough air leak into one side of the plenum might do it...

What are the fuel trims and lambdas doing on the two banks immediately after they become active, before the misfire, and after a reset of the fuel trims? If they are dragging the fuelling far enough out to cause misfires, then the lambda sensor sill report silly values because the misfire admits air into the exhaust.

If I've understood, it ran correctly for a minute or two, indicating that it probably all went wrong when it went closed-loop, meaning likely a lambda sensor problem. When the lambdas were disconnected, were the fuel trims also reset? It could be that it was running with a stored fuel trim value even though the lambdas are now out of the equation.

A reset of the stored fuel trims and then a datalog of all parameters form cold until the misfire ensues would be interesting.

[JamesV6CDX]

One possibility I can think of is that the throttle shaft is bent, meaning an imbalance in the air supply to the two banks at idle, but, now I think about it, I think that one's blown out of the water by the manifold multiram valve being open at idle, so that would balance the airflow anyway.

A big enough air leak into one side of the plenum might do it...

What are the fuel trims and lambdas doing on the two banks immediately after they become active, before the misfire, and after a reset of the fuel trims? If they are dragging the fuelling far enough out to cause misfires, then the lambda sensor sill report silly values because the misfire admits air into the exhaust.

If I've understood, it ran correctly for a minute or two, indicating that it probably all went wrong when it went closed-loop, meaning likely a lambda sensor problem. When the lambdas were disconnected, were the fuel trims also reset? It could be that it was running with a stored fuel trim value even though the lambdas are now out of the equation.

A reset of the stored fuel trims and then a datalog of all parameters form cold until the misfire ensues would be interesting.

Hi kevin,

Fault codes were cleared upon lambda disconnection, it had no influence, still missing from idle at open loop

Plenum seating was triple checked. I'm wondering about the black inlet bridge now though!

The misfire on 135 btw is pretty much from cold, unlike the 246 problem which was only from hot..

[05omegav6]

Purge valve and ecu coolant temp sensor plugs the correct way round?

[JamesV6CDX]

Purge valve and ecu coolant temp sensor plugs the correct way round?

Yep 100%

[05omegav6]

Do you normally remove the fuel rain and inlet manifold together, or do you split them?

[JamesV6CDX]

Do you normally remove the fuel rain and inlet manifold together, or do you split them?

Together, as one

[05omegav6]

Do you normally remove the fuel rain and inlet manifold together, or do you split them?

Together, as one

With the loom still attached/unplugged at bulkhead?

[JamesV6CDX]

Do you normally remove the fuel rain and inlet manifold together, or do you split them?

Together, as one

With the loom still attached/unplugged at bulkhead?

I usually unbolt it, move it out by a couple of inches for access (but no more so as not to stretch the wires) - I then reach in, unplug it, and remove

[05omegav6]

Do you normally remove the fuel rain and inlet manifold together, or do you split them?

Together, as one

With the loom still attached/unplugged at bulkhead?

I usually unbolt it, move it out by a couple of inches for access (but no more so as not to stretch the wires) - I then reach in, unplug it, and remove

Ok no real chance of issues there then...

[Kevin Wood]

Can you see petrol injector durations on the live data? Are they the same bank for bank, give or take a little?

Any knock sensor activity being reported?

[Steve B]

No problem putting live data up..Just need to no under what conditions Ie; hot/cold engine/rpm Etc;And exactly what readings 

[JamesV6CDX]

Can you do us a snapshot from an immediate cold start today?

[JamesV6CDX]

From stone cold, through until it's warmed up, at idle rpm

[Steve B]

From stone cold, through until it's warmed up, at idle rpm

Ok james ...live data gives you about 3 readings per second.... Thats a lot of data to put up