1989 Jaguar XJR xjr 3.6 sport 1989 (rare) Steering problems

i have a 1989 XJR 3.6 sport,and what the problem is,the steering wheel is not straight when the road wheels are? the steering wheels position is slightly to the left and not straight,which when driving is causing the car to turn very hesitatingly almost over-steering because the response to the steering and the wheels are not responding quick enough or correctly,i have had the steering rack changed and i have had the car aligned the problem is still there,please i would be ever so grateful if you could give me some advice to what the problem could be? as i wont drive the car due to the unsafety of the steering.all the best and thank you