N62 4.4i misfire

[subsea]

HELP...any electrical gurus out there who can shed some light on a misfire  4.4i n62.. have carried out the following

Recon engine fitted due to burning oil and misfire cylinder 1 and 2
engine fitted...misfire continues on cylinder 1 and 2
No power at all from the engine ?
timing checked and is set
changed plugs, moved coils around...still same misfire
changed injectors around and still cylinder 1 and 2 misfire
changed ECU and DME out, still same problem cylinder 1 and 2

Rgds
Kevin

[X5Sport]

Have you traced the wiring all the way from the coil packs back to the ECU?  You've tried pretty much everything else so I would start looking at the wiring itself all the way from the connectors to the coil pack.  Any damage such as insulation wear (including inside any clamps), cracks, bare wires etc can all add up to a problem.  You might have a grounding fault, or a break in a conductor, short circuit, open circuit, bad pins, corrosion etc.

You also need to check whether or not you are getting any voltage on the coil packs.  No voltage, no spark!  You may need to access a pulse checker such as an oscilloscope to see the voltage spikes.  You should be able to compare a good one against cylinders 1&2 with a dual trace scope.

Have the fault codes been read to see if anything is being picked up?

[shadrack]

wheres kkx isnt this his speciallity?

[subsea]

Have checked to see a spark but of course i don't know if the spark is strong enough or regular enough. Will check wiring back but have option of a wiring loom for 100 quid.. spending way too much on the beast now though as it seems i am chasing my tail.. fault diagnosis is only "misfire" cylinder 1 and 2

[kkx5]

[quote="shadrack"]
wheres kkx isnt this his speciallity?
[/quote]

??? I'm here...don't worry. subsea: Not vvt ecu issue? What software you or garage using?

[shadrack]

[quote="kkx5"]
[quote="shadrack"]
wheres kkx isnt this his speciallity?
[/quote]

??? I'm here...don't worry. subsea: Not vvt ecu issue? What software you or garage using?
[/quote]

thought you were the man for this job