150HP Optimax Power Output Low

[EuropeanAM]

As Joe mentioned, the TPS should really be ruled out as well (voltage sweep test is a good method of checking).

At some point, it may become more advantageous to enlist the hands-on expertise of a Certified or Master Tech.

[lilredrooster]

Don't give up on me yet EuropeanAM! Really though if I can't figure this out soon then I'll pull the boat out and take it to someone. So here's an interesting update:
I purchased a set of non-OEM fuel injectors to test out the leaky fuel injector question. I figured if they fixed the problem then I could determine which one had been bad and replace that one with an OEM injector and put the old OEM injectors back on. So I just bought these for troubleshooting. First step for changing these out is to depressurize the fuel rails. So I depressurized the fuel rail and then pressed in the air schrader valve too...but when I did this I noticed some fluid came out. I didn't pay much attention to it thinking it was just some moisture. I replaced the fuel injectors. Even though I had depressurized the fuel rail (using the schrader valve)...I still got blasted with fuel when I pulled the first injector (started with the starboard side). I thought that was weird. Then tried to start the boat and it wouldn't even stay running for 2 seconds. Sounded terrible. I immediately removed the new fuel injectors and put the old ones back on. HOWEVER, when I went to depressurize the system again I took a look at the "moisture" that came out of the schrader valve and noticed that it was oil. And the more I pressed it the more oil came out...highly aerosolized but still oil. That doesn't seem good. Anyway, I put the old injectors back on and the engine fired up again with its usual poor idle/miss but ran as it had been. Shut it off and checked air schrader valve again and still oil in there. Why would there be oil in my air rail?? Oil enters the engine through reed valves in crankcase doesn't it? The only thing I could think of is the air compressor is oil-cooled. Uh oh though. Any ideas?

[JOE54]

water cooled oil lubricated compressor is only way pure oil can get in rails

[EuropeanAM]

^^^^ Most likely source...

[lilredrooster]

What would be the failure on the air compressor and what could I check to confirm this? Are there any serviceable parts in there or would it require replacing the entire compressor?? Thanks.

[JOE54]

ring failure , entire replacement required

[lilredrooster]

UPDATE: I went ahead and pulled my boat out of the water so I could work on this issue in my garage. Since we suspect the air compressor has failed I removed it. Before I purchase a new one I wanted to make sure this one is bad so I removed the compressor head. I took pictures of the inside. Since we suspect that the rings have failed and oil is getting into the compressed air I assumed I would see signs of a failure along with oil all in the air portion of the head. But everything looked completely normal and fine to me. Should I still replace this compressor or what are yall's thoughts? Would I be able to tell if I have excessively leaky rings or not?
IMG_5972.jpgIMG_5973.jpgIMG_5976.jpgIMG_5977.jpgIMG_5978.jpg

[JOE54]

are you perfectly positive its PURE OIL IN AIR SIDE of system

[lilredrooster]

Joe, I will put the air compressor back on tomorrow and fire it up and take a picture of what comes out of the air nozzle. When I was pressing it a few weeks ago my thumb would be covered in a green foamy slick substance...and the oil is greenish/bluish colored. I gave it a sniff and did not smell any gasoline. I will do it again tomorrow.

[lilredrooster]

Ok, put the compressor back on and fired up the boat. Pressed the air schrader valve and no oil came out this time. Just air. Sooooooo...that's confusing. But it appears as though there is no oil getting in the air anymore. I'm not sure why there was so much oil coming out last time I checked. The only thing I can think of is that it was right after I put the original injectors back in. I had depressurized the fuel and air rails when I swapped injectors but still when I pulled the first injector out there was a blast of air and fuel that came out behind it. Perhaps this blast pushed some oil or something into the rail from the compressor or something weird like that?? But right after I did that I noticed a bunch of oil in the air rail. But I guess it was a fluke? So I'm really kinda back to square one with troubleshooting this boat. It has a very poor idle but runs at top speed ok (with maybe a little reduced power) but at top speed under a heavy load like when there's a lot of people in the boat the engine will miss. I looked down the air intake with the throttle open (engine not running) and there was a ton of crud all along the walls in there...looked like oil splatter...is that normal? My plan going forward right now that I have the boat out of the water is to check everything I can: tps voltages, injector resistance, etc. Perhaps I should remove the fuel rails and send the injectors off for cleaning? Perhaps I should take off the VST and clean it? Any suggestions for next step? Any tests yall want me to run?

[lilredrooster]

So starting back at square one I decided to check fuel and air pressure since this was always done while reaching over the back of the boat with gauges taped to the engine. The air pressure read good 80psi. But the fuel pressure only read about 86psi...so definitely low I'd say. After the engine is shut off the fuel pressure drops to about 60psi in 10 seconds. I guess I should start exploring fuel delivery system and fuel pumps?

[aussiejake]

Just noticed you haven't mentioned whether you have or haven't replaced / rebuilt the low pressure pulse fuel pump. This little unit is critical to the idling / running of the motor, very easy and cheap to rebuild.

[lilredrooster]

I just removed it yesterday. I'll probably open it up today or tomorrow. Thanks for the suggestion.

[JOE54]

arent you glad you didnt buy that compressor yet,recomend removal of rails and send to INTEGRITY INJECTION, ^^^^^#24 above

[leonreno]

Did you ever check the reeds?

[JOE54]

+1^^^^^^