98 Merc 200EFI Fuel Pressure

[jbl_91762]

I am trying to figure out what will cause my fuel pressure to show 50PSI at idle then drop to 40PSI with throttle. Thanks to forum member H20kie, he sent me helpful info. Also thank you to Mr Carson as he is helping also but cant take all his time over the phone. So the manual states to replace the fuel pressure regulator if it drops below the spec of 34 to 36 PSI as the fuel pump pushes 90 PSI. The manual does not say what to do if it is above as mine is. CC told me to pull the reg and check the screen if clogged which I did and there was no screen. Not sure if the idiot boat shop I have dealt with pulled it out and cleaned it, then forgot to replace it and now there is No pressure regulated or if its something else. So would that missing screen cause excessive fuel to push through or is it something else now?
In the mean time CC and I are all over the internet searching for a regulator but thanks to Covid, Merc is back ordered. If anyone knows a place that sells one OR forum member that has one laying in an old motor please PM me asap. The part number is 8140122. Thanks.

[jbl_91762]

Installed new OEM pressure regulator and problem still there fires up great but once pressure builds, I am guessing its flooding the motor. Nobody knows why the fuel pressure is way above the limits at 50??? Anyone? Is there a problem or circuit that is allowing fuel pump to pump accesivly? Please help gents, hard to believe nobody has run into this issue.

[Dave Strong]

Try a different gauge.


Dave

[jbl_91762]

Able to track down a fuel pressure regulator and that seemed to be the problem. I am now at tolerance with 34-36 PSI but now I have a problem elsewhere. BOAT (break out alot more thousands)