good day sir, i own a gen2 jdm pajero with a 4556 Turbo intercooler engine, and for the past months i noticed that my pajero has been hard starting during cold starts even if all the glowplugs are glowing good. and the bad thing is, after it cranks to start for 15 seconds, a big grey-ish smokescreen is emitted by the exhaust. and while it runs or is in idle, my exhaust still emits this grey ish smoke that smells very unpleasant. and to add to that, my pajero has very bad fuel mileage, let's say around 5.5km/L-6km/L on city and 7-8km/l on highway. what could be the problem and how much would fixing the problem cost?