Working on a 91 w350 non inter cooled 5.9 cummins. I’m having trouble with bleed down. I had to crack injectors to get pickup to start and use a shot of ether to get it going. Once going it will run like a top until you turn it off. After sitting for a few minutes it will not restart without cracking injectors and some starting fluid again. I took off the lift pump and the diaphragm seemed to be screwed up so I installed a new one. Now that I have it on the pickup can sit for 20-30 minutes and then restart but still has some bleed down. If left overnight it will not restart without “normal starting procedure”. Any help would be greatly appreciated.