I just got my car back from XPAuto and they had done quite a bit of work:

Engine related items:
Fuel filter was replaced
Rear head rebuilt new head gasket on the rear head
2 bad injectors replaced

Here's my issue. When I drove the car at first, it was 88 degress and when I drove it for a bit, the car started to buck when >20% engine load was introduced. I took the car out around 9PM and the car drove perfect for an hour...

I have replaced TPS, IAC, plugs and wires have been changed, distributor rotor is new, cap is new.

I am stumped... Feels like fuel related, but car ran great in the evening... Fuel pump???