I am wondering if anyone has had experience with rough idle and producing high egts. We replaced the ficm (not currently flashed to truck) a little while ago and it ran good. The other day it started running real rough and missed real bad. Went out to start it today and after cranking forever, it started up and ran fine. After about five minutes it was running real rough and the egts were over 500. Then it died and won't start. I added Stanadyne to the fuel thinking that maybe an injector could be plugged. I'm new to this whole thing so any input or advise would be much appreciated. Thank you.