Hello, I have a big problem with my Matiz 2000. It is powerless and, at idle speed, once the normal working temperature is reached, revolutions raise and drop continuously, generating a low oil pressure. Even more, the car jerks considerably at any gear and both when cold or warm. In order to stop the jerking a little bit, I need to keep the clutch pressed more than usual, generating a disgusting burnt clutch smell. I've replaced everything already, including: cylinder head, valves, filters, fuel pump, sensors, TPS, IAC, spark plugs, wires, camshaft, timing belt, hoses, among many other things, but nothing got better. The car has got a good compression, around 160 pounds. I really do not know what else to do. Thanks in advance for any help you could give me.

Once the engine warms up, my Matiz loses power considerably. I was told it might be the egr valve because some black smoke is also released when accelerating sharply. But oil is not consumed, and the engine has been recently serviced. Hope you can help me.