Hi guys, I need some help on diagnosing my work truck, hope I've come to the right place. First problem is that it starts extremely hard when its less than 40* out. It just started doing this the end of last winter. Next problem is that sometimes it will start to idle really rough and smoke white if I come to a light or am trying to park. Sometimes it will even shut off if I dont get on the gas quick enough. If I rev it up to 3k it will give a big puff of white smoke and then come back down to a normal idle. One time it would not start again until I checked the oil to find it was 6 quarts low! It started doing this last summer, and has only done it a dozen, maybe 20 times. It went in to get serviced last month and they changed the oil and replaced to fuel filter, but it didn't help anything. I've been told it could be the HPOP? thanks in advance.