hi when I've pumped hand pump on top of filter on my mitsi delica 2.8 intercooled turbo, it gets firm but is soft again 20 secs later. it also has trouble starting on cold mornings only to cut out 30 secs later ,then harder to start when I pump it she starts up easier , have by past filter now will see what happens. if this fixes the problem ,what do I need to do with filter hand pump etc?