hello everyone i have a 87 gt it has the megasquirt 2 ecu trick flow intake aluminum heads ( not sure what type ) 1.6 roller rockers f cam y shape pistons alum radiator msd distributor . when i got it was told it has a base tune needs to be tuned but she wont stay running while o2 sensor heats then it loops idle up and down air fuel goes from 13.3 13.4 to 20.4 21.2 .22.3 back to 13 to 12 to 19 to 12 in a matter of seconds she will smooth out a bit after warm up but drivability is not there she surges like she wants full trottle or should i say like she wants to run, low speed bucking is bad help what could be problem