This one has me baffled. Car starts fine, idles fine, never misses a beat when warmed up. But oh dear when first started I can increse revs (gently to about 1500 to 2000 and it will misfire very badly, revs dropping right back, smoke, everything. Been through pipes, turbo egr throttle etc., everything and no apparent mechanical fault. I discovered that unplugging the ECU engine temp sensor (replaced just in case) fools the engine into thinking its hot and it will run perfectly even though its really cold, problem is the ecu thinks the engine is hot and so the cooling fans run full tilt all the time.
I can only think this is an ecu program mismap. Anyone else experienced this or have any suggestions as it's most embarrasing to drive 1st thing in the morning?