if I put the route to the link of my isp I put out the networks from my vpn
That won't happen if the selectors are in place. If the traffic-selector does not match the private traffic then yes, it would be routed out to the internet. If the tunnel is down and the packets match the selector, then the BIG-IP will try to establish the tunnel and even if the tunnel fails to start the packets will not be routed out the internet.
You mentioned earlier that you had a gateway pool and I think there could be a problem there if you're trying to use the pool. Like I say, it's too complicated to give specific advice without asking for data that you should not publish here, hence my recommendation to contact a partner or F5 support for analysis.