fuel pressure

[bobimo]

I have a 1999 mercury 200 hp efi s/n og8866278. How long should the fuel system hold pressure, the fuel pressure starts at 38psi and within and hour drop to 25psi this is with the motor not running, cannot find ant external leaks, is this pressure drop ok.

bob

[EuropeanAM]

Perfectly fine. For diagnostic purposes, I look at the pressure at idle, under acceleration, and 15/30/60 seconds after engine shut-down. Most engines lose up to 3-4 psi by 60 seconds (a few may hold pressure like a champ for hours).

[bobimo]

got lucky, took the front of the manifold off to see if any of the fuel injectors where leaking. found the bolt that hold the fuel rail loose, one was ready to fall out, tighten the bolts and everything seem to be working. had taken the boat to a repair shop because it would start but not run, they said they found two injectors bad and trash in the fuel pump. this the same shop that tested all of the original injectors and said they were good. will not use them again.

bob

[EuropeanAM]

Yikes!