On ever 5 min or so do you thank it could be the foot valve

Could be several things. I assume you replaced thr foot valve because the same thing was happening. Correct? And with the new foot valve in place you have the same problem, Is that correct? If that's the case then chances the old foot vale was OK and you'll have to look elsewhere.
Here's what I would do.
Close the house shut off and let the pump pressure up. Does the pressure hold now? No? Then close the valve that is after the gage and on the hose service line.
Pressure still dropping? If shutting down the house and the service line doesn't stop the pressure loss then all that's left is the pump suction line and the foot valve. Soooo, run the tests and get back to with the results. Good luck, Tom

Have done alll that except suction line don't really know how to with out pulling out 80 foot line allso when turn power off lost prime

have done alll that except suction line don't really know how to with out pulling out 80 foot line
So you've isolated the house. Then isolated the service line and still the pressure falls when the pump shuts down?
But you said that you replaced the foot valve. To replace a foot valve the suction line has to come up. Are you sure it wasn't a check valve you replaced? All that's left is a leak in the suction line.
Go back and recheck your tests and if they check out you'll hafta bite the bullet and pull the suction line.
I had another thought, If it was indeed a check valve and you installed it backwards that would give you the situation that you now have. Good luck, Tom

Have done alll that except suction line don't really know how to with out pulling out 80 foot line allso when turn power off lost prime

I did indeed pull the it up to change the foor valve. Whitch is the suction line the small one ? And thank you so much for your help I thank it is a leak or a bad foot valve I have about bad new stuf be for lol. That is all it can be right.