2000 F250 5.4 doesn't start right

[baseball1]

Hello, I have a 2000 F250 SD with a 5.4 in it. I recently had my mechanic replace a leaky intake gasket and ever since that was done my truck starts like crap. it doesn't fire right up like its suppose to. It will fire up then cough and sputter and die. The second time it will fire up. He replaced something, a little chrome thing that controls the high idle when it first starts, I can't remember what its called, and that changed nothing. Friday he tore it all back apart again, The intake and all involved with that. Now it takes a second and third time to start up and still doesnt go into high idle like its suppose to. He's being great with me to try and get it figured out but it's making me mad. This is my main vehicle and I need it to last awhile yet. I live in northern lower michigan and it's been very cold lately just to let you know incase it helps. The truck has 228000 miles on it and 49000 on a new motor. Please help! Thanks