i have recently rebuilt my pontiac formule 350 tpi setup. It was running fine with no problems untell about a week ago. I noticed a small miss when at idle......usually when cold but does it when hot too. The car is running pretty good but its when its at idle it has a little miss. I rplaced almost everything on the engine...about 85-90 % is new parts. Also i have noticed that my gas milage is starting to suck. i am thinking about taking it to a shop to be looked at but wanted to see it i could fix it with your suggestions. i replaced the plug wires but didnt really help. any ideas would help.......THANX

 

Did you check the timing and for any air leeks.