Ok the mate got his car back Monday. The mechanic was stumped on the problem as it did only di it when it was warmed up. He ended up replacing the fuel injectors, fuel reg and the fuel filter. It appers to be ok now but its strange how temp affected the injectors the way it did. He was stung just over $600 for the repairs.

Just replaced my spark plugs yesterday arvo, The ute started to suffer from the symptom you're describing when taking off. at first, I thought it was s**t fuel.

when I pulled the leads off, No 1 spark plug lead was pretty loose. the lead boot must of pop off, it wasn't making a full contact with the spark plug causing the arc to jump across.

Do what I do, just replace the cheapest part first. cheaper then what a mechanic would charge.

* check the leads to the coil packs, did you cut a slit on the lead boot before you press it back on?. reason I ask is it might still have air in it. when air is heated up it expands, if it expands in a tight rubber boot it'll lift the contacts. leads & spark plugs don't last long in those conditions.

trace it yourself & you shell find.