2004 22V running rough and alarm

[hoppas]

Hi All,

My '04 22V (Marine Power 5.7L EFI) is running rough and alarming when I get over about 3500 rpm. Oil pressure looks good, temp is around 170 (never over 175), oil level is good, and I have a lot of water coming out the exhaust manifolds when I open the valves. I just replaced the impeller, distributor cap, rotor, and plugs.

I have been way too busy at work and still running on last year's winterization gas. I drained some out of the fuel filter and looked for water but didn't see any separation.

The engine sometimes runs smooth, and sometimes seems to have a miss. If it detects a miss, will the knock sensor set an alarm? I replaced the knock sensor about a year ago as the old one's threads were looking shady.

Even when it alarms, it doesn't seem to enter limp-in mode. I can continue to run it up to top speed.

Ideas? Bad gas? Is the thermostat causing a problem? I saw some posts where the temp should be around 140 or 160, not 170. I also saw something about the alarm going off if the tranny temp is high. How can I check that?

Really appreciate any ideas. There are no dealers in the KC area so I'm either towing to Missouri or fixing it myself.

Thanks!

Jeremy

[GUY_RPM]

If I am not mistaken this is a Mercury motor which you should be able to find a repair shop that should be able to scan it for you, if it is beeping at you it is kicking out a code. I just had to have mine scanned by a non Tige dealer because there are no Tige dealers within 4 hours of me. Once they scanned it they found that the throttle position sensor was bad causing it to run bad and die when put into neutral.

[hoppas]

It's actually Marine Power, not Mercury. Same problem with the dealers though. Mine idles fine at the moment.

[boatwakes]

The marine power engines have the same MEFI3 or MEFI4 ECM's so the diagnostic analysis is the same across the board and any marine shop should have the computer to scan them. You will not get limp mode unless you have a MEFI5 ECU. So, what kind of beep? Prolonged/doesn't shut off, multiple, 2 every 5 seconds...? Each beep has a related problem: prolonged is overheat of engine, transmission oil or low oil pressure in the engine, multiple beeps are associated with sensors and 2 beeps every 5 seconds with fuel pressure or fuel pump. The miss could be due to a stuck injector as your saying you still have the fuel running in it from winterization. If you winterized it by spraying fogging oil into the throttle body, you probably have a stuck injector because you're supposed to use a fuel supply with 2 cycle oil in it at 30:1 ratio for fuel injected motors. The fogging oil can and will cause injectors to stick open or closed during the first few hours of running.
A miss will not set a knock sensor off as the 2 are generally not related but a noisy lifter, rocker arm or actual knock itself will tell the computer to retard the timing until it stops. Keep us posted and give as much info related to the problem as you can think of.

[hoppas]

It's a prolonged beep - doesn't stop until I shut the boat off. I can immediately re-start and the beeper stays off until I once again come up to around 3000+ rpm. I noticed the temp gauge hovering near 170-175 so maybe it's a borderline overheat. I'll check the cooling hoses, etc. for a flow restriction.

My understanding is that the water is routed through the tranny on the way to the engine, and tranny fluid is full, so what could be causing a tranny overheat? Where is the tranny temp sensor connected?

I appreciate all the help and ideas, thanks!

[Harbs]

This is exactly what my boat (2006 22 V) is doing, did you figure out the problem?

[Aspidaso]

Not overheating, my 22v runs 170 to 175 on the gage all day long. I Was getting the steady alarm and found the oil Pressure sending unit was bad. In process of trouble shooting I replaced the iac and boat runs MUCH better.