First I would check that the fuel pressure gauge is accurate.
Might be relevant why the heads and injectors were replaced.
In‑Water Test done in gear under load.
1. With a vacuum gauge and a fuel pressure gauge in place, operate the boat throughout the RPM range and record the pressure
and vacuum readings.
2. If the fuel the supply vacuum reading is greater than 2 in. Hg (7 kPa) , find and correct the fuel supply restriction.
3. If fuel pressure is less than 40 psi (276 kPa), but greater than 13 psi (90 kPa):
a. Verify that the vacuum from the fuel source is within specification. If the vacuum exceeds 2 in. Hg (7 kPa) , excessive
fuel restriction exists. Correct the fuel restriction before proceeding.
b. If no excessive fuel supply restriction exists, replace low‑pressure fuel pump.
4. If fuel pressure is 13 psi (90 kPa) or less and no excessive fuel supply restriction exists, replace high‑pressure pump and fuel
pressure regulator.
IMPORTANT: It will be necessary to sea‑trial the boat following repairs to be sure that the pressure and the fuel system vacuum
remain within specification throughout the RPM range.
Probably time to pull the cool fuel 3, pop the top cover and look at the paint inside.
