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[05omegav6]

Car has just had replacement loom fitted...

Developed 246 misfire. 246 coilpack loom repaired, (ground wire was corroded, so bypassed and replacement tail fitted)

Now runs, but lumpy. No light on.

After scanner shows no codes, but pedal trick suggests 0150.

Revs ok, just idling like the alps.

Bank 1 trims are... Short 25%, Long 0% 02 sensors both at 0.015-20

Bank 2 trims are... Short -25%, Long 0% 02 sensors at 0.850

Any ideas?

[biggriffin]

Had this couple years back, turned out was a faulty coil pack, and spark plug, also flashed up  maf code aswel.
New 135 and set of plugs

[05omegav6]

Throttle body clicking away.

Unplugged Maf and idle settled, plugged back in and ok, unplugged it and misfire returned.

Still no Eml/spanner light.

Bank 2 sensor 1 replaced and no more 0150, so that's dealt with that.

[05omegav6]

Maf swapped with original one to rule it out... No change, although it showed a higher idle airflow on the live data. 8.5kg/H vs 5.0 kg/h.

Coilpack swapped yesterday to rule that out...

Looking at second loom change... Do also have spare throttle body (original to car) and a spare ecu.

[05omegav6]

Loom was originally changed to solve intermittent and persistent o2 codes, not the usual 0420/0430.

Change solved the 02 codes, but introduced the 246 misfire  codes, hence the loom repair... Still persistent although no lights and starts ok from cold, getting progressively worse as it warms up.

[Andy H]

Bank 1 trims are... Short 25%, Long 0% 02 sensors both at 0.015-20

Bank 2 trims are... Short -25%, Long 0% 02 sensors at 0.850

Loom was originally changed to solve intermittent and persistent o2 codes, not the usual 0420/0430.

Change solved the 02 codes, but introduced the 246 misfire  codes, hence the loom repair... Still persistent although no lights and starts ok from cold, getting progressively worse as it warms up.

Have the wires got crossed? Is the 135 wiring plugged into the 246 sensor & visa versa?

[biggriffin]

Loom was originally changed to solve intermittent and persistent o2 codes, not the usual 0420/0430.

Change solved the 02 codes, but introduced the 246 misfire  codes, hence the loom repair... Still persistent although no lights and starts ok from cold, getting progressively worse as it warms up

As coil pack gets warm, the hair line cracks open(expansion) then you get a misfire. Try a new, coil pack, no cracks.

[05omegav6]

No, cross referenced with original loom prior to fitting and Factory diagrams 

Coilpack loom impossible to confuse as plugs are colour coded to the packs... Also 246 plug won't physically reach the 135 pack.

Car has had alot of work done this year, including complete new exhaust with 3.0 cats.

[05omegav6]

Loom was originally changed to solve intermittent and persistent o2 codes, not the usual 0420/0430.

Change solved the 02 codes, but introduced the 246 misfire  codes, hence the loom repair... Still persistent although no lights and starts ok from cold, getting progressively worse as it warms up

As coil pack gets warm, the hair line cracks open(expansion) then you get a misfire. Try a new, coil pack, no cracks.

Makes sense, previous pack is very tidy second hand, current one is, I believe, new (I didn't fit it). Same fault with both, ie no change.

[Andy H]

No, cross referenced with original loom prior to fitting and Factory diagrams 

Coilpack loom impossible to confuse as plugs are colour coded to the packs... Also 246 plug won't physically reach the 135 pack.

Car has had alot of work done this year, including complete new exhaust with 3.0 cats.

I meant the lambda sensor wiring. My reason for asking is that there was a car on the forum that had the fuel trims going up on one bank and down on the other after a gearbox swap. Turned out that it was very easy to mix the wiring up as it is long enough to reach either sensor.

[05omegav6]

Serek fitted the cats, so wiring was taken as correct. Also, the way the loom runs on an auto, it's almost impossible to get the sides confused as the bank 2 plugs are tied in with the gearbox primary plugs, whereas bank 1 are with the gearbox speed sensor 

Just reread your post... Suggestion that the bank 2 sensors are arse backwards?

[serek]

any news? I know car, and its on going problem there was few sets of lambda sensors fitted to solve p0150
when we was fitting cars other day plugs where marked to make sure don't get mixed up .

[05omegav6]

any news? I know car, and its on going problem there was few sets of lambda sensors fitted to solve p0150
when we was fitting cars other day plugs where marked to make sure don't get mixed up .

Likewise when we swapped the loom

[Andy H]

any news? I know car, and its on going problem there was few sets of lambda sensors fitted to solve p0150
when we was fitting cars other day plugs where marked to make sure don't get mixed up .

Likewise when we swapped the loom

Any chance of the wires being crossed before Serek saw it?
The thing that has caught my attention is the way that the short term trims are up 25 on one bank and down an equal amount on the other which makes me think that the feedback from one bank is being fed back to the other  and via versa.

[Andy H]

Visa versa.........

If it isn't the lambda sensors then I wonder if it is possible for the injector wires to have been swapped? From memory it wouldn't be easy but becomes possible if you unclip the lid on the cable tidy between the two banks of injectors.

[05omegav6]

Visa versa.........

If it isn't the lambda sensors then I wonder if it is possible for the injector wires to have been swapped? From memory it wouldn't be easy but becomes possible if you unclip the lid on the cable tidy between the two banks of injectors.

All six injectors fed from common plug

Swapped out offending sensor as it's possible the routing of the wiring strained it as it exited the sensor.

Original O2 faults were persistent and intermittent 0130/0135, which the loom swap cured. Unfortunately it replaced it with the 246 misfires.

Be easy enough to swap the bank 2 plugs to rule out the -25 value.

[tigers_gonads]

If it was me, I would stick it up on ramps / stands with the engine running and the code reader plugged in then un plug the lambda sensors one by one just to make sure 

It is pish easy to get them the wrong way round 

[Kevin Wood]

Maf swapped with original one to rule it out... No change, although it showed a higher idle airflow on the live data. 8.5kg/H vs 5.0 kg/h.

Should be up around 12-14, IIRC.

What are you reading the data with?

Any possibility of a large air leak into one bank? (brake servo pipe, etc)

[Kevin Wood]

Also, see how it runs with both Lambda sensors disconnected.

[05omegav6]

Vac pipes checked and rechecked. Plenum was removed to swap loom and everything put back in good order... Similarly, brake servo pipe removed to give clearance for 246 loom repair... Again rechecked.

Code reader is the diddy Autel one, though pedal trick gives more consistent answers. That said code reader throws up codes as pending, pedal trick confirms the codes, yet light still not on

[Andy H]

Visa versa.........

If it isn't the lambda sensors then I wonder if it is possible for the injector wires to have been swapped? From memory it wouldn't be easy but becomes possible if you unclip the lid on the cable tidy between the two banks of injectors.

All six injectors fed from common plug

Swapped out offending sensor as it's possible the routing of the wiring strained it as it exited the sensor.

Original O2 faults were persistent and intermittent 0130/0135, which the loom swap cured. Unfortunately it replaced it with the 246 misfires.

Be easy enough to swap the bank 2 plugs to rule out the -25 value.

From the common plug a little loom runs between the inlet runners to 6 individual plugs for the 6 injectors. If you don't take the plastic cable guide apart then they should never get muddled - if someone did take it apart and confudled their cylinder numbers however.......

[05omegav6]

That loom hasn't been touched

[biggriffin]

Vac pipes checked and rechecked. Plenum was removed to swap loom and everything put back in good order... Similarly, brake servo pipe removed to give clearance for 246 loom repair... Again rechecked.

Code reader is the diddy Autel one, though pedal trick gives more consistent answers. That said code reader throws up codes as pending, pedal trick confirms the codes, yet light still not on

Could be an O ring hasn't been seated correctly.

[Andy H]

What history does this car have? Is it one that has been owned by a forum member (or members)? Has it ever been known to run sweetly?

[serek]

What history does this car have? Is it one that has been owned by a forum member (or members)? Has it ever been known to run sweetly?

since I know car always had lambda issue
had gearbox replaced
then we replaced 2 or 3 lambda sensors
then I think Al swap plugs back to front to make sure we don't mixed them up , next cats
and now loom

Edit:
ecu was replaced too