Help Troubleshooting mercruiser

[Majick]

I have a 1988 Mercruiser 5.0. The other day while out while running at 2800 rpms the motor died. I tried to crank for about 30 secs and got nothing. I tried again with the throttle wide open and it restarted. I ran it again at around 2800 rpms and it died again. This happened a few times and then it ran fine the rest of the day.

I was going to look at the fuel pump but I see a bunch of wires and am now confused as to how it all works.

Any insight is appreciated before I start replacing parts that may not need replacing.

Thanks

 

[Bondo]

Re: Help Troubleshooting mercruiser

I was going to look at the fuel pump but I see a bunch of wires and am now confused as to how it all works.

Ayuh,... 'n I'm confused by that sentence...

Is it a mechanical pump, or electric,..??

 

[Majick]

Re: Help Troubleshooting mercruiser

The pump is mechanical but when i follow lines to the fuel water seperater it looks like a selonoid or something.

 

[Don S]

Re: Help Troubleshooting mercruiser

Can you post a picture? It doesn't sound like an OEM part. Possibly a flow sensor for a fuel flow meter.

 

[Majick]

Re: Help Troubleshooting mercruiser

I am unclear as to what everything is (the wires) above my fuel water separator filter.

 

[vandentr]

Re: Help Troubleshooting mercruiser

The wires you see are just mounted to a bracket on top of the fuel filter/pump housing. There's a solenoid (gizmo on top), trim connections (two black wires), and a resetable fuse button (red button). I'm not ure what that white striped wire dangling from the harness connection up above is all about, that's definitely not "normal", but none of this has any relevance to your gas/water separator filter or fuel pump.

The black filter's just hanging there, waiting to be changed, not unlike an oil filter. Note that it'll be nearly FULL of fuel when you remove it and to make sure the new one is filled with gas before installing it as well. Hopefully though, the old one isn't sealed to the mating surface due to age and won't put up too much of fight when you attempt to remove it. From there the fuel is delivered to your carb, where there may be a second, inline, filter in the carb housing depending on the model.

Also, the pickup tube in your fuel tank could be the culprit, all gunked up with sediment...

Good Luck!
TVB

 

[Majick]

Re: Help Troubleshooting mercruiser

Thank you for that info.I got the boat about 3 months ago the fuel tanks are new and all the lines not sure about the pick up inside the tank. I would think so also this problem seems to happen when i put fuel in the boat and not any other time .Do you think i should replace the fuel pump.I am going to change the filter today.

 

[vandentr]

Re: Help Troubleshooting mercruiser

I'll have to defer that question to those who are more familiar with the 5.0 engine. Regardless, I'd simply make sure the fuel "path" from the tank to the carb is clean and clear before doing anthing else...

 

[Pete104]

Re: Help Troubleshooting mercruiser

Especially, if someone said "Oh yea, the tanks are new."