START OPLA ASTRA G problem

My problem is the Sigante. I have an Opel Astra G 1.7 DTI Motor Isuzu of the year 2000 and 56000km.
The thing is that I only use it on weekends, when I started the Saturday, it starts the first one, after being all week, but from time to time after there I have echoed some short journey I start again and it does not start, it costs it a lot and in the end it starts but almost to the limit of exhausting the battery.
He took him to the Opel and they didn't see anything by not failing them.
Algien would tell me what it can be or that I can see Garcias

Good,
you would have to give some more clue, that happens to you when the engine is hot, or cold after stopping it for the first time.

It is true a little more data would be use, but in reality the intermittent failures are a bit complicated because generally alomento to take it to the mechanic or want to check it do not do it, so you say a current problem is difficult to determine, if you want when you love you the failure Cheke the intention of the current and if the pump throws a good amount of fuel, because the fact that in a week does not pass, and within a week it does not strange.

Normally it happens to me when after a journey of about 5 minutes in city and stop an hour
later the slope to start.
If the journey is exhausted by a Sunday and I stop it, the Saturday starts the first.
Thanks for bothering you to answer.

Saves Mira There is a recurring fault in the Opel, Chevrolet and GM engines, Chekea the temperature sensor, you want this evil and send you a very long injection pulse, and tend to drown the engine, it can be there, Chekalo to see what happens.