Nissan Repair: nissan terrano11 2.7tdi 1997, radiator leak, head gasket

Question
Hi,I recently blew my head gasket on my truck after having a radiator leak.I have had a used engine which came from a year 2000 model fitted another radiator a new clutch and water pump!The engine management light is on when I start the truck it acts as I have my foot on the accelerator (revs up )and I have noticed it blows out a cloud of smoke.It drives ok but a little ragged and the tick over seems inconsistent.Please could you advise me on what the problem might be and the solution as the man that put the engine in is not interested and please don`t tell me I need to buy more parts for it I am nearly broke!
Thanks for any help you can offer. alex (who knows nothing )

Answer
Hi Alex -

If you lower the idle, does the engine die, run rough, or smooth? Does the truck run fine at higher speeds, or still rough? What color smoke is coming out of the exhaust, blue, white, or black? If it is white, does it dissipate quickly?

Answers to these questions is important to the diagnosis -

Thanks
and get back to me
aloha
calvin