I bought my car in March, 00 z28. The guy I bought it from put a walbro255 in it back in December. Now I have to cycle the key a few times to prime the system and my pressure gauge only read 25lbs at idle. The car hesitates under load and I lose all pressure once I turn the key off. Bad pump or possibly something came off in tank?

Thanks in advance

 

I would say in tank loose hose