2004 Merc 5.0L MPI bogging under load

[KetchiMan]

New guy needs help......

2004 Merc 5.0L MPI Bravo is intermittently bogging down under load. Sometimes it goes just fine, but sometimes I have to shut it off and restart it to make it work. It will generally run up to about 10-15 mph but then starts to sputter and won't go any faster. Twice now it has bogged and won't do more than idle, but shutting off and restarting seems to "fix" that too.

Guy at the dock said "high pressure fuel pump"........
Would this cause the problem? What else might?

Does it have 2 fuel pumps? (high and low pressure??????) If so, where is the high pressure pump? There appears to be a fuel pump (it's attached to the fuel line) located under the alternator on the starboard side, near the front of the engine.

Engine serial # is 0W18920 (I think....... the first and last numbers are a bit rubbed off.....last digit could possibly be a 6, first digit looks like it could be a U, but that doesn't match up with any of the other merc numbers I have seen).

Any sound info is appreciated as you could just about write what I know about boat engines on the back of a matchbook with a crayon..........

Thanks,
-Nick

 

[Bondo]

Re: 2004 Merc 5.0L MPI bogging under load

Ayuh,.... Check, 'n change the fuel Filter.....

 

[KetchiMan]

Re: 2004 Merc 5.0L MPI bogging under load

Ayuh,.... Check, 'n change the fuel Filter.....

Yeah, that's good advice. I probably should have mentioned... I tried that first. Didn't fix it. Actually, it seemed to have worked at first, but nope, it started bogging again. Thanks though! Any other thoughts?

 

[Pete104]

Re: 2004 Merc 5.0L MPI bogging under load

Have you got fuel pressure gauge & a vaccum gauge?

 

[KetchiMan]

Re: 2004 Merc 5.0L MPI bogging under load

Have you got fuel pressure gauge & a vaccum gauge?

Nope

 

[Bondo]

Re: 2004 Merc 5.0L MPI bogging under load

Originally Posted by Pete104
Have you got fuel pressure gauge & a vaccum gauge?

Nope

Ayuh,.... Hire a Mercruiser Tech....

Ya can't fix nothin' without Tools...
Throw in the fact it's a 'puter controlled motor,...
Ya need Tools, And a diagnostic 'puter...

you could just about write what I know about boat engines on the back of a matchbook with a crayon..........

There ain't no Easy Button....

 

[KetchiMan]

Re: 2004 Merc 5.0L MPI bogging under load

Ayuh,.... Hire a Mercruiser Tech....

Easier said than done up here. Here is only one outfit in town that works on them and there are about a thousand stories about people getting screwed over by them. I'd like to start learning how to work on my boat myself. I have done a bunch of work on cars, but things aren't all the same on a boat, so I've got a bunch of learning to do........