Lopeing under load

[batmmannn]

I have noticed that my N/A Supra seems to lope under light load. Curious as to any easy diagnostics or remedies? Under some acceleration it is not there just when you are trying to cruise along with minor throttle.

Any ideas? Could this be caused by overheating or air in the cooling cause I have not bled the system and my overfill bottle had not been filled yet? It's full now though, the cooling system filled it and then I had to add more coolant to the radiator. I might have air still in the cooling system. The car has not overheated according to my temp guage. As it is not tagged yet I have only snuck the car out a few times up here on the mountain for 20 minute test drives. I am going to park it facing up a hill and see if I can get it to burp up the last air with the cap off.. Any comments? Don't think I have a BHG cause the oil looked normal when I did the oil change, No accumulation or milky film under the oil cap. the cylinders all read the same or close compression, I am getting no white smoke from the exhaust, the plugs looked good and tan on removal. Thanks, Scott