Vacuum was 3 inHG . Which i know is below what Don S says in his stickey but it was running fine when i first installed it and would maintain 8psi fuel pressure even at WOT so i was pleased.
So after sleeping on it i decided to use the vacuum gage to try and decipher if anything in the fuel system was causing a differential pressure/drop in vacuum and something interesting happened.....
So i ended the day with the motor running for a while, fuel pressure fading to 0 then the engine dieing and unable to remain running..... Started today with 8psi fuel pressure and her running like a dream. Completely confused... none the less....
1. Installed the vacuum gage between the fuel filter and the pump and had 8psi and 3 inHG
2. Ran it for 2 to 3 more mins to see if i could recreate the drop in pressure and sure enough the pressure started dropping to 4 psi but i still had 3 inHG
3. With the fuel pressure gage almost on 0 now i still had 3 inHG
4. Cut the boat off and relocated the vacuum gage to before the fuel filter and even with 0 psi on the fuel pressure gage she started up and i had 2 inHG before the filter.
5. put the test "T" fitting in place of the fuel filter and started it up and with the fuel pressure at 0psi the vacuum gage read 1.5 inHG
6. Put the system back to how i had it pre-test and ran it again just kinda of contemplating and she cut off and would start but for a second again. Put the vacuum gage back into the system between the fuel filter and the pump and turned the pump on and cranked the motor and got 0psi fuel pressure and 0 inHG
So i know that i have two variables in the my test so its pretty much worthless but it did give me some interesting observations. It appears to me that the pump is bad but for the life of me i can't explain it. This will be number 3, and this one had less than an hour runtime on it. Also, why would it start strong and fade?
