Services engines light Blinking 97 VR6

I have a jetta GLX VR6 year 1997, the service engine light is ON and OFF, blinking and the car are very trembly and without force, what can be the fault? Thanks!
Tego un jetta GLX VR6 1997, la luz del motor (services enginen soon) se prende y apaga, paraprea y el carro esta muy tembloroso y sin fuerza.