I have a 99 1 ton chevy 454 that I removed the stock ecm over a year ago and swapped to the 411 ecm for more tunning options. Ever since the swap if I start the truck when it has been started with in a hour from shutting it off you have to give it gas once it starts to keep it running like 1200 rpm for 10-15 seconds then it is fine. Thinking that has something to do with the idle air control. But can't figure out what to change. But the bigger problem is for the last couple weeks it has not wanted to idle at all. you almost have to drive it two footed or bump to neutral for stop lights it may do it then you can drive on the highway or down the road a mile or two and then it may not do it again for the rest of the day. Then today we got snow so I started the truck to pull out of garage to start plowing my 1600 driveway and turn around and it would not stay running. So I went to parts store and replaced cap and rotor again with ac delco parts only 8 months old on old stuff. Seems like these vortec motors are notorious for caps. I put it all on this mornig and then plowed my driveway again then about 2 hours later went and plowed another drive and ran great so figured that fixed it. Pulled truck back in garage and 5 hours later just went out to push my driveway off again and ran like crap again will not stay runnig have to drive two footed. I have looked for over a year trying to find some tunes of guys that are using the 411 on their 454 and can not find any to see what I have wrong. I know it is started with a 5.7 tune from a express van and changed from there I am thinking something from the 5.7 did not get changed right for the 454. Please take a look at tune and see if you can help.