Good afternoon, try to review the compression of this engine this will identify you if it is low if it is so throw a drop of oil through the injectors and re -measure the compression you can verify if so if the problem comes from cylinders or valves, if this was correct, try to throw a self -arrange for admission (little) sell it in spray this must give you a result that at least the engine manual and that of the Opel Monterrey that carries this same or identical motor encourage and运气