My problem has been coming on slowly, it seems whenever starting the car hot or cold i have to depress the accelerator pedal once before turning the key and it will start no problem, use to not have to do that. now that it is getting colder outside after doing this procedure on the first start of the day the engine seems to have a low rough idle and sometimes have to hold the accelerator with slight pressure to keep the car from stalling, also some of the time the idle will slowly surge a few times, once the coolant temp gauge starts to rise the problem will go away. it is only the first few minutes on a cold start morning of say 50 deg f or less. since i bought the car in april 2009 i have replaced all 5 injectors, all 5 glow plugs, both fuel filters (twice), performed diesel purge (twice), ran algae killer through the tank several times, and add diesel kleen fuel additive at every fill up. also i have adjusted the valves twice, last time was about 5000 miles ago. the engine once a little warm runs like a champ and has never had an acceleration problem at any time. i have put 28,000 miles on it, so i drive it alot. total mileage on odometer shows 168,000+ miles. need some advice on possible cause. could this be a lift pump problem? thanks, Gary S.