Really hard to anticipate just exactly what the actual problem is since we can't see the car from here. Could be and usually is something not of the norm. But the normal stuff is a good place to start!
timing , not just ignition , but valve(timing belt?). What is the reading from a vacuum guage hooked in after the throttle at idle? steady and at least 17"? spark plugs fouling with gas? Checked fuel pressure with gauge?