Rebuilt 2004 Optimax won’t run over 1800 RPM.

[Gjohnson0497]

First things first…
2004 Mercury Optimax 225
Serial: 0T971232
smart tow gauge installed from previous owner (helps quite a bit with engine data)
Vessel is a 2004 Triton TR200X if that matters at all.

Just finished rebuilding my 3rd optimax motor. Motor was rebuilt due to low compression on #6 and #1. (Probably could have gotten away with just new rings) but anyway…
Rebuild consisted of all internal parts (pistons, rings, bearings, rob bolts Etc…) injectors were sent out for cleaning and testing and all 12 came back good to go.

finally got it all put together, primed the oil, primed the fuel, charged the battery, fired it up and awesome! It runs first try (like i know what I’m doing after all). Very Smokey startup of course, due to all the assembly oil, and it finally cleared out after 2-3 mins at idle on the hose in the driveway. I’m pretty confident at this point that I’m ready for a lake test. Put lower cowling back on, top cowling, load it up and head to the ramp 3 mins down the street. Fire it up in the water, idle out of the launch area, make sure engine is up to temp, start to increase the throttle to 900-1000 rpm. Motor running fine at this point. As soon as you get on it for a holeshot it bogs down and will not go above 1800rpm.

Took it home, checked my fuel/air pressures
-rail fuel pressure just turning key 40psi then drops to nothing
-rail fuel pressure engine running at idle 90psi but cheap gauge is bouncing erratically
-rail air pressure engine running at idle 80psi gauge bouncing again.
-pressure gauge hooked directly to VST Schroeder valve is 20-22Psi no matter running or just turning key on to prime.
-primer bulb is hard for every scenario above and stays consistent
-fuel pump electrical plug is getting good 13.2vdc and you can clearly hear the pump running when primed.

took apart the VST, filter is clean, both pumps work on bench test with power probe.

Im i missing something? Why is it running like crap now. Motor ran fine before rebuilding it just low on power (felt like it was over propped and just lacking the punch a 225 should have.)

At this point I’m lost. Just ordered new walbro pumps for boost and high press just to rule them out.

[JOE54]

what does fuel psi do when engine is turned off from idle , you say 40 psi then nothin at key on is a problem

[EuropeanAM]

Also need to know if you hear a warning horn, AND if there are any faults logged in the Freeze Frame (Fault) History.