I have a 1998 7.4L MPI Mercruiser. It recently started having issues with starting after it's been running for a while. It starts fine the first time and runs like a champ. After stopping, often it will not start again. I put a fuel pressure gauge on it and noticed that when it starts (the first time) the pressure is about 32psi. After stopping it and then attempting to restart, there is no pressure. I disconnected the fuel pump and checked the voltage at the pump when I turn the key... seemed to be fine so I assumed it was a fuel pump issue so I replaced the fuel pump. Got it all back together, started it a few times and it seemed to work. Took it out on the lake and it ran like a champ. Stopped it for a swim and the problem came back (i've learned to just leave the fuel pressure gauge on it so I can watch what's happening). Anyone have any ideas? I'm wondering if it's a fuel pressure regulator issue? When I swapped the pump I put the old one back on... thinking I should have replaced it too.
Thanks for the help.
Thanks for the help.