Viperchad

Do you happen to have a part number for those solenoids?

SDFever

They are generic daytime running head light relays. If you walk into a CarQuest, they will have it. Just take the old ones with you.

I can't remember the number.

Keith Atlanta

I got mine off www.mercruiserparts.com make sure you use your engine serial number or take them with you because there are two types - ask me how I know this...


Swap them around, there are 3 of them anyway.

Viperchad

OK, so I replaced all the relays and still same problem. Alarm sounds at about 2500 rpm. I hooked up a pressure gauge to the fuel rail and found that in the "on" position...pressure is about 45-46. Once I fired up...at about 2k the pressure dropped to 34-36psi. I am thinking it's the fuel pump. So, question is....is it the high flow or the low pump? Also, can't find the damn part numbers anywhere. The motor is a 09/04 build date. Thanks!!

SDFever

Slow down just a bit and think it through. I bet if you pull your vaccum line off the reg at idle it will jump back to 45-46.

Did you run the boat with the fuel pressure guage hooked up at higher rpm's?

Based on what you're saying it does not sound like fuel. It's normal for the pressure to drop around 5LBS after it's running until it stops pulling vaccum.

That's the only reason why I suggested the cumbersome process of pulling your other pump and trying it on the bad motor. It's NOT the best idea out there by far.


If you have the older style KoolFuel under the engine mount on the port side of the engine you will not be able to buy that pump alone anymore. You'll have to buy the whole kit with cooler but there's a valid reason.

Put a scanner on the engine along with your pressure gauage and duplicate the symptom. Watch the data page specifically.

crayolacrazy

I have been on the boat its driving me crazier ,

Viperchad

Didn't do that, but pulled the regulator off the good motor and switched it to the bad motor. Same problem. So it's not the regulator. I'm at a loss. Maybe the housing on the sea pressure pump is scored too bad and still not creating enough pressure? We checked all vacuum lines again and didn't find anything out of the normal. What a PITA.

Raylar

You've got fuel pump issues or feed issues to the coolfuel pumps that is dropping the fuel pressure under load and when it stalled the engine, the fuel pressure at 2K rpms should stay about 40-43psi.
The engine will go into guardian mode and sometimes throw a cam and cranksensor fault when it stalls. There is no real problem with the cam or cranksensors as you would not even be starting or running with crank and cam sensor problems.
You probably have one of the two pumps in the cool fuel clogging on the feed side, a clogging fuel water seperator filter cartridge or one of the pumps is giving up. The fuel relay code you found could also indicate a bad relay or intermittant connections in the fuel pump relay circut.
In any event I think your problem is fuel pump or fuel pump relay based and the sea pump pressure even though low would throw a low pressure code and be accompanied by a usual overheat if it were a guardian accompanied problem.

Best Regards,
Ray @ Raylar

launchpad475

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any resolution on this problem?