Injector loom harness

Oil in the injector loom can take a while to clear out, you can examine it all you want and you won't see any, but it's still in there. It gets into the actual wire, inside the insulation around each wire.
At the ECU end, depending on how badly the connectors were contaminated, you might have to go deeper to clean things out. The red plug has a white plastic insert in it and the oil can get inside there too. At the ECU itself, oil might have made its way past the plug and socket, so that could require cleaning too. You might have to remove the lid and do some cleaning out in there.
In most cases, an aerosol spray of IPA or an electronic switch cleaner which does not leave a residue should be used especially in the ECU box, try not to touch the parts in there, some are probably "static sensitive". Leave everything dry after cleaning.
This bloke's website shows you how to do the cleaning:

http://www.discovery2.co.uk/Injector_harness.html

Was the loom genuine one? ...aftermarket looms can be crap from the beginning, also did you keep the interior plug pushed down while you connected the external to it at the head? otherwise it may not make the best contact there either

Had what sounds like a similar problem recently and did the same, changed the injector loom, cleaned the ECU plug etc and problem remained.
Turned out to be the fuel pump, may or may not be the same in your case. Mine self diagnosed when it completely konked out and couldn't hear the pump priming anymore.

Hi guys. yes it was a genuine loom. I think its the existing in the engine loom working its way out. just checked it after a week of it running fine. Found no oil in the ecu so hoping problem cured. im going down the root of a full service now so new fuel pum,oil filter,MAF sensor
etc.

Sam Shores said:

Hi guys. yes it was a genuine loom. I think its the existing in the engine loom working its way out. just checked it after a week of it running fine. Found no oil in the ecu so hoping problem cured. im going down the root of a full service now so new fuel pum,oil filter,MAF sensor
etc.

Click to expand...

Well, keep an eye on it for a wile anyway.

just an update been away with the truck for 6 weeks still misfiring getting sick of checking the ecu for oil for it to be empty! anyway booked it into the garage who told me i needed a new maf, ok bought fitted still no joy, then they told me i needed a new turbo as the waste gate was seized, looked into this a bit more myself and turns out the waste gate wasnt seized it was turned out on its threads to much, couple of turns back in then a bit more for optional boost and its running like a dream! thankfully all down to forum hunting or i could have been down a few hundred on a new turbo

You would expect to see 13 threads on the wastegate rod if it is at std settings.

Cheers