99 optimax issues

[KingdomBusinessCharters]

Started with the port engine running ruff and not turning proper rpms at full throttle. found out I had external spark issue with a wire. replace it and its good now. Now the starboard engine is giving me issues. checked wires to be sure and saw nothing to speak of. Replaced all the plugs today and still seeming to have issues. It runs a little ruff an turns fewer rpms than the port engine.



both engines at full throttle, also not water pressure gauges.



starboard engine and water pressure @ 5 psi



port engine and water psi @ 10



tonight after the spark plug change. I don't get it... Cant get it into my mechanic hes too busy, so im left to try and figure this out on my own... with no success... and banging my head... Im at a loss.

 

[schematic]

Re: 99 optimax issues

Its nice when you have 2 engines to compare!

Compare air pressure and fuel pressure to start with.
Also try swapping the ignition modules from one engine to the other.



Wouldn't hurt to inspect water pumps and poppet valves and thermostats.
While you're at it, clean the screen that filters water for the air compressor. (just for maintenance sake)

 

[KingdomBusinessCharters]

Re: 99 optimax issues

try swapping all six from one engine to the other ? and I have no clue of the other stuff your talking about, I mean I know where the T stats are. looks like I have to pull the rails to get them off as one screw if pretty much hidden

 

[sidenberg]

Re: 99 optimax issues

logical if the engine is turning less RPM's the water pressure would be reduced. 2 things come too mind. Although you dont see any obvious wire issues still could be culprit since that corrected the other engine, especially if they are old. Also could be a fuel line issue. Maybe check or replace lines and filters if old. Maybe air filters? You running quickleen or something similar to clean out fuel injectors?

 

[schematic]

Re: 99 optimax issues

try swapping all six from one engine to the other ? and I have no clue of the other stuff your talking about, I mean I know where the T stats are. looks like I have to pull the rails to get them off as one screw if pretty much hidden

While I admire your courage.....I don't advise you to go much further without getting a manual and familiarizing yourself with the system. Air pressure and fuel pressure are essential for troubleshooting. Until you measure them, its all just guessing.....

 

[KingdomBusinessCharters]

Re: 99 optimax issues

ok heres what I did. I had one wire on the starboard engine that was rusty on the inside of the spark plug boot. So I replaced the wire. So with that in mind it got some kind of moisture in it.I took that coil pack off and swapped it with one on the other engine to see if problem persisted. Nothing changed it still idles at about 550 rpms which is correct. Port engine rpm gauge said at idle it was about 1k. I rev'd the engine and rpms came down and matched starboard engine at idle. so they are now about the same.



haven't put her back in yet to run it at FT again. I have had TPS issues with the motors since I bought it. I heard the wear out and get sloppy so maybe time to replace

 

[KingdomBusinessCharters]

Re: 99 optimax issues

While I admire your courage.....I don't advise you to go much further without getting a manual and familiarizing yourself with the system. Air pressure and fuel pressure are essential for troubleshooting. Until you measure them, its all just guessing.....

I have a service manual.

 

[schematic]

Re: 99 optimax issues

I have no clue of the other stuff your talking about

Thats what manuals are for.....and you said you have one....