normal vacuum at idle, on tube going to FPR. 5 inches okay? 240 efi

[brevard2002]

trying to judge the health of the reed valves and general state of the engine.
My thoughts are the vacuum is lower than it should be and the MAP sensor on computer is feeding a little too much fuel.

pretty easy, just pull hose from FPR and connect to vacuum gauge and start for a couple seconds. Boat on trailer
thanks
Perry

 

[brevard2002]

oaky , some more data,
i hooked a hand vacuum pump to MAP sensor, the engine runs much better with 15 inches of vacuum,
less smoke, and to me engine is smoother, like it is too rich when vaccum is 6 inches.
if i let the MAP sensor go to 0 inches of vacuum the engine stalls.
the vacuum at the manifold port is 6 inches.

 

[brevard2002]

I got confirmation that is correct vacuum.