Hi, I have an 85 300zx non turbo that I have just completed puting in a newly rebuilt lower end. I have put less than 5 miles on the car because once it's warm it seems to bog down when I press the accelerator, as if the choke were on (which it of course does not have.) It runs great for about 10 minutes then the trouble starts. It will still idle ok but I have immediatlely shut it off when this has happened to prevent any damage. I'm thinking it is probably some minor emissions related component failing or not hooked up properly or that the engine just needs to be broken in. It has new plugs, cap, rotor, wires, head gasket, oil pump. Any Ideas? Thanks.