Change of the time of the engine isuzu 2.3 man

Te3ngo problems with the time of the my Truck Chevrolet Luv year 1997 presents a minimal fault in the start and is a little remained, the mechanic told me that possibly the belt was poorly placed, dandelted and needed and I took advantage of changing the belt, what are the parameters of time as it should The soul, greetings and thanks

The distribution strap, you must change every 80 or 100 kl.