300tdi dropping revs.jumping feeling

My 300tdi has just had new pas pump and belt fitted at same time it overheated on way home n it had air lock in system.air lock gone.when you give it full throttle it goes up in revs then itl drop from 3000 to 2000 and back up again n feel like it jumping.


Any help as iv checked air filter and fuel is in it.

If you half throttle it is fine but full throttle it jumps

Please save me as wife wants me get rid but i love it

air lock or short of coolant ,when revved water pump will pull coolant and laeve part of engine short, air filter is okay i presume ,i would fit clear plastic pipe in between filter and front banjo bolt fo feed to pump ,good idea to leave it in as you can check for air entering system at all revs ,i would epexct air or restricted fuel ,if its govenor fault in pump it would need checking at specialist or replacing check fuel first

It was air lock in system as he landrover mechanic pulled the pipe off water pump by mistake.so air git in.it had full bottle wen i collected it and had keepfilling it up.used 6 litres in 10 miles.so took it back nd got it sorted then the jumping he sed wud need looking in to so 4t id try on here and see wat could be wrong

it just wasnt filled up after removing water pump ,you have to remove both bungs one on rad and one on thermostat housing and fill till both overflow and he aint very good if he didnt know that,level in expansion bottle isnt indicator of coolant level in engine,try whats been said first as he sounds like hell cost money

Got ya.so can ya dumb it down a bit for me please james or do me a step by step guide

theres a few things that can cause irratic revs air in fuel,can be best checked with clear pipe in feed to pump which is front pipe,lift pump is often culprit but checking bubbles in clear pipe is best way ,air pipes blocked ,split ,delaminated inside causing restriction,not so likely but worth checking ,or pump govenor ,would need checking by specialist not mechanic, if yours was disco auto with edc ,sensors would need checking

Mine is 300tdi auto.wats edc stand for or look like and il get it looked at

Electronic diesel control and if you have got a maf unit between your airbox and turbo the engine has EDC