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[PaulW]

Ongoing issue with the Elite (been going on for ages...)

Poor idle after a while (judders, feels like running on 5cyls, revs from 300 to 800rpm on its own)
Missfiring from 0k to about 4krpm under load.  As soon as it gets past 4k it shoots off as it should

Now had it upto a Tech2 today and got these values...


O2-Loop BLM Idle 1 - 213
O2-Loop BLM Idle 2 - 3

No idea as to why or what is going on...

Any idease??  (looks towards the Master)

[Jimbob]

To add, there was a code 19, so A new crank sensor is also needed.

[PaulW]

To add, there was a code 19, so A new crank sensor is also needed.

Will be bought this week... 2.5 and 3ltr are the same aren't they?? (so can carry across to the new engine when fitted)

[Kevin Wood]

Hmm. Big difference between the banks at idle and very little under load.  Perhaps the EGR sticking open or a leak into one of the exhausts? Air leak into one bank only? (plenum seal perhaps)?

Did you try exercising the EGR with the Tech 2? Did it respond normally?

Kevin

[Jimbob]

Hmm. Big difference between the banks at idle and very little under load.  Perhaps the EGR sticking open or a leak into one of the exhausts? Air leak into one bank only? (plenum seal perhaps)?

Did you try exercising the EGR with the Tech 2? Did it respond normally?

Kevin

Nope, didnt think of anything I could do with tech2 to further aid diagnosis.

[Kevin Wood]

If you manually open the EGR and note how far it opens before the idle goes to pot it can give a clue to its' condition. Just as easy to blank it off with a bit of coke can for a quick check though - or clean it out and see if that improves matters.

Kevin

[PaulW]

I'll can the EGR tomorrow see how it behaves with it.

[PaulW]

Well that made no difference to running or performance...

[Kevin Wood]

Well that made no difference to running or performance...

<scratches head>

Not a vacuum leak I suppose? Multirams working OK? SAI pipes and the little rubber links to the exhaust manifold OK? Breather pipes still connected and no splits?  :-/

Kevin

[Marks DTM Calib]

Are the vac pipes to the rear multiram connected up correctly? (i.e. vac feed to the nose of the actuator?)

[Marks DTM Calib]

Are the vac pipes to the rear multiram connected up correctly? (i.e. vac feed to the nose of the actuator?)

Just to explain my thinking about the above.

The idel valve connects directly to the chamber that feeds the 1-3-5 bank....the idle air for the 2-4-6 bank has to pass through the open rear multiram flap.

Hence if the flap is shut then the idle air for the 2-4-6 bank would be very restricted (it would have to pass through the small ports on the EGR and breather ducting!).

This would explain the poor and hunting idle and the sudden 'no issues' at high revs!

Its the only logical one I can come up with at the moment.

So check it and check the actuator is not permanently open (move it with your fingers to see if the idle improves)

[PaulW]

Are the vac pipes to the rear multiram connected up correctly? (i.e. vac feed to the nose of the actuator?)

Just to explain my thinking about the above.

The idel valve connects directly to the chamber that feeds the 1-3-5 bank....the idle air for the 2-4-6 bank has to pass through the open rear multiram flap.

Hence if the flap is shut then the idle air for the 2-4-6 bank would be very restricted (it would have to pass through the small ports on the EGR and breather ducting!).

This would explain the poor and hunting idle and the sudden 'no issues' at high revs!

Its the only logical one I can come up with at the moment.

So check it and check the actuator is not permanently open (move it with your fingers to see if the idle improves)

Yup, remember you tech-2'd the multirams when you did the camcover gaskets due to the same issue & said they were fine..  I've gone over the vac lines again though, they all go where they should & revving the engine up I can visibly see the rams flicking about.  Tried moving with fingers too tho, no improvements (still juddery)

[Kevin Wood]

Don't suppose you've got a blocked cat or something? Something has caused an inbalance between the two banks as far as the fuelling is concerned. They breathe from the same plenum volume as long as the rear multiram is open at idle so that should rule out the inlet side. The other asymmetric item is the EGR, which hasn't made a difference.  :-/

Cat  blocked or a major air leak into the exhaust upstream of the lambda sensor on one side is the next possibility.

Other thoughts are cam timing out on one bank?

Kevin

[Marks DTM Calib]

Blocked cat would fast melt an air injection rubber coupling piece!

Injector assembly....worth swapping it with the one off your ex-plod to rule out?

[PaulW]

Blocked cat would fast melt an air injection rubber coupling piece!

Injector assembly....worth swapping it with the one off your ex-plod to rule out?

Still not 100% sure on the ex-plod yet as cant test it proper till I get the exhaust fitted...

I've got the injector setup from the LPG kit too, easier to just pull & swap the injectors over from that...  I'll give it a go...