Short problem description- When truck is cold(less than 30), would start hard and chug a lil then run great when warm. No other issues. Glow plugs and trlay are good. Took truck to shop and they verified plugs and relay is good. We suspected possible injector oring problems. Sent injectors off to be tested while they were out. Results were they flowed fine at idle but at higher rpm range they were down about 10 percent. Need new ones. Truck has 120,000 on it and I use stanadyn lube additive. Is there a better route to go than just buying new ones or any input would be greatly appreciated.