My opel corsa engine has been rebuilt and the engine is now running smoothly. The only problem is that there is a blck smoke from the exhaust when the engine is running and too much petrol is used up. The reves count is also highI took the car for machine diagnosis and it showed that the throttle sensor had a problem. I replaced the throttle sensor but still getting the same problem and the car does not have power to move. When I unplug the throttle sensor when the after starting the reeve count goes down to about 0.5 and the car now has power to move but black smoke still there. I am currently using the car with throttle sensor unpluged. What could be the problem?