Rough Idle

[siddy_fi]

Howdy, got a 2001 GU 3.0L Turbo Diesel. The engine runs fine 98% of the time but when at idle (stopping at traffic lights and stuff) the engine runs rough (not all of the time though).
A couple of presses of the accelerator pedal and it fixes itself. Some people say injectors might be the cause, my mechanic is unable to diagnose as he cannot communicate with the ECU.
Recently the glow plug relay had been replaced, could this be a cause of the problem? Anyone have any idea what the problem may be? Many thanks.

[Winnie]

The engine does not need the heat from the glow plugs once it has been running a little while, so I'd rule that out as being the problem.

[alfonso]

try replacing fuel filter could be dirty and losing pressure when at idle check air cleaner also. These are the cheap maintenance things we should all do anyway but rarely do. If you have a snorkel is the inlet turned to the back as some people do and vehicle is struggling for air

[siddy]

Took the MAF out and gave it a clean. Engines purrs like a kitten... No issues whatsoever...