Slow on starting , holds back when driving, even on an A road or motorway my vehicle is mitsubishi shogun long wheel base 2.8 turbo diesel

Personally I would NOT drive it. Get the turbo repaired/replaced! Modern vehicles have engine sensors that will cause even more running problems as they aren't detecting the turbo doing it's job.
Diesels will run without a turbo but they are usually ridiculously slow and really really struggle to accelerate.This is especially true on smaller diesel engines like those you get in cars and smaller vehicles. I had a turbo fail on a 2.0 litre diesel engine and with my foot hard down it took me well over a minute to hit 50mph, and that was before I got to any hills.

have the variable vanes in the turbo checked for correct operation
there is an actuator that is vacuum
electrical sensor controlled and the vanes may be sticking at slow engine operations as on traffic
the smoke color indicates incorrect air/fuel ratio and the turbo is a point to investigate

Could be a loose or broken engine mounting!

most vehicles do have a yellow light that comes on and usually after engaging 4 wheel drive you have to reverse for 2 to 4 feet, after that your 4 wheel drive should be working fine

Put a diesel additive in and see if that helps.

Your power steeringpump is already bad. Change it before it causes the rack to spoil or worst of all before it causes an accident.

Good luck and rate this fixya

hi its a fuel pump seal needs replacing ....

I got my book from ebay.com 
good luck  Grace

Try selecting 2 wheel drive and reverse for 20meter .

Did you ever sort this ? I've a similar overheating issue and just wondered ? Thanks ...