I have a problem of the truck when you start it up it runs way rich it does this till it gets warm. As in as long as the temp gage reads 210 it seem to run fine but if I let the truck get down to 180 or so it will run like crap. anyone have any ideas on what would cause this. I've just recentle replaced the front o2s, cleaned the maf, and replaced the IAC. I was going to do plugs this week since the truck has 60,000 on it are tr55 good for an NA setup and what should they be gaped to for a 5.3L

 

gap the plugs at .060". if the truck is a 99-03 check the fuel pressure regulator.

 

already checked that vacuum line was dry.