im New to these forms I’m hoping someone can help me out with a proble on my truck I just bought ! So I got a 2001 excursion it has roughly 340k miles on it . So the problem that it has is that when it’s plugged into the block heater it starts no problem, I let it sit up without it plugged up maybe like two days and it refuses to start. I can keep cranking and cranking and it wants to catch and start but it keeps stumbling on itself and blowing smoke out the exhaust pipe . I just installed new gp and gps still no help when it finally starts it runs like it’s got a skip and run just really rough. When it warms up it clears up and drives fine . The hpop res is like 2-3 inches from the top when it sits .after I crank it or let it sit for a day it’s almost at the top, icp at cranking is around 600 psi when I let off from cranking it drops pretty rapidly. I replaced the fuel filter as well and I don’t know really what else to do I feel like it’s a injector that is just shot ??? Any help would be great!