I have a Corsa b 1.6i. My car was working perfect and friday I took my battery out and put it back the same afternoon. The next day I tried starting my car and it refused to start so I kicked started the car. It backfired and started but would not rev up pay 2000rpm. I switched it off and started again but would not change. I have changed the plugs thinking it was old, but still the same. I have checked fuel air n spark, all seems to be doing its required duties. My mechanic has failed to sort my car out and it has 3 weeks. We tested crank airflow and map sensor and all working but last tried he retarded the timing backwards 3 teeth and it revs up to red line but still lacks a large amount of power. It drives now atleest but will not climb a slite steep hill even in 1st.
What might be the reason?