Sea pump Pressure / Block pressure Low

[dolemite_1]

Hey guys,

Thanks for any help in advance. I have a new to me 2000 formula 280ss w/ fairly new (2006) 350mag horizons (OW359452) about 250 hrs. I just bought this boat and ran it fine for about 2 hrs and then got alarm horns. Was cruising around for about 45 min then idleing around for about 2 hrs. When i went to give it gas and cruise again I got a solid alarm horn. I then idled back to marina w/ 2 beeps every minute. Scanner show a low sea pump pressure. Things that have been changed recently before I bought the boat by a marina mechanic:

Couplers and r-bar mounts for both engines
waterpump impellars for both engines
Cool fuel housing both engines
Shift Cables
Batteries

I have attached the live history that I just pulled from the engine, and I have downloaded manuals 31 and 33. What should I look at first

Any suggestions?

Thx

Brian

 

[NHGuy]

Re: Sea pump Pressure / Block pressure Low

My initial thought was the waterpump impeller in that motor isn't making it. After seeing your readout, I'm not so sure. In some of the reports it's happy as can be. Try, briefly running the motor up off idle, to say 1200 rpm and see if the display changes. Maybe the pump is working but not correctly. It looks as if you had OK coolant temps on every reading, I'd expect trouble with a poor seapump.
Also did you notice the water temp reported 32 F each time. Maybe you have other issues. I'd replug every connector you can find. After that it's time to swap the sensor from the other motor and check that the report is true.
Take this advice as what it is, seat of the pants.
If someone more knowledgeable than me comes along good.

 

[dolemite_1]

Re: Sea pump Pressure / Block pressure Low

So the solid alarm only comes on when I bring it up toward 1200 rpm's It runs fine when i idle around which makes me think something is working but not properly enough. Also it is a closed cooled engine

 

[Don S]

Re: Sea pump Pressure / Block pressure Low

You need to check your sea-pump pressure circuit. With the engine NOT running you are showing 10 to 20 psi (Should be 0) but when running you only show 0.04 psi at any rpm. The .04 might be fine at low rpm, but not higher rpm and the ECM knows it. Turns on the Guardian alarm and probably limits the rpm.

 

[muc]

Re: Sea pump Pressure / Block pressure Low

2nd checking sea pump circuit and sensor.

Also noted that you have low battery voltage at key on. Low voltage during cranking can cause some strange problems.

 

[dolemite_1]

Re: Sea pump Pressure / Block pressure Low

Thx for the direction guys. Going down to check it now. Also don't know if it matters but I can run the boat at cruising speed usually for about 5-10 min before the alarm sounds