Very strange problem with RPM

[alourake]

I'm baffled and need help please. I have a 2005 Monterey with a VP 5.7 GXI-f. When throttling up, the boat gets up on plane, the RPM settles in about 4K to 3800 and runs there. Any jockying the throttle after that for waves or what ever reason, when pushing the throttle back up it simply won't reach any real RPM over 1500. No matter if I pull the throttle back to idle and push it up again, same thing, it just will not power up. No limp mode, just a sluggish motor. Now if I turn the key off and start it again, it runs fine. Thus resetting the computer and everything is good until I reduce power and try to push it up again. I have replaced the throttle positioning and the manifold pressure sensors with no change. Fuel filter is new, both fuel pumps are running. Any ideas, I've exhausted my knowledge? Thanks in advance for any help or suggestion you might be able to offer.

 

[tpenfield]

Greetings,

I see that you have been a member for a while, but this is your first post. You really need to have the computer diagnostics to troubleshoot a fuel injected engine, particularly the situation that you described.

Other means would just be guessing and result in randomly replacing parts.

It would be interesting to see (via the computer) what the engine 'thinks' is going on after your have throttled back and trying to throttle up again.