Mallory 4110 rebuild?
 

So i finally got my mallory set up with new 3/8 lines return and feed but I'm still having problem with the fuel pressure! the pump goes noisy then quite and sometimes i get great pressure with great fuel flow through a glass filter other times i get 0 pressure and obviously little flow, i think it may need a rebuild? i brought it off eBay so not sure how old or if it has been rebuilt before? is there any way of checking or does is sound like a rebuild would resolve it?

thanks in advance

I bought it off ebay... Same reason my fuel pressure isolator works only when it wants.