Fuel filters

aero3113

Are there any other fuel filters besides the main fuel filter on a 5.7? The main filter was changed last week but today on the way back from an overnight stay I noticed some surging at high RPM's. If I backed off the throttle a little bit the surging went away.

Babyboomer

None that I know of maybe your injectors are dirty

aero3113

It's a carbureted engine. When it would happen,once I backed off and came off plane then powered up it would go away then eventually come back or some times it wouldn't come back.

brianluck

Dirty jets? Try some carb cleaner

212rowboat

when it happens, and if you can, put your hand on your fuel pump and see how hot it is... it sounds like it is giving way, on you... (if it isn't the filers starving the engine, or gummed up jets, that is)... you may need a new fuel pump...

or..

the fuel pump gets it's energy from the starter solenoid on start-up only, and then it goes to the hot 'keyed' wire.. it's purple.. it could be that the hot purple wire is shorting due to corrosion or bad connection at the connection points, which would limit constant voltage to it.. and cause a condition like you describe. Give that wire a look-see from the key all the way back, and make sure it's connected well, and corrosion free...

good luck!!

aero3113

Is it possible that the filter is clogged already? I had them replace it when the oil pan was replaced. They did a full tune up and the boat ran great, put about 4.5 hours on since. I did have the same issue when the boat went in for repairs but like I said ran great when I got it back.

212rowboat

I sure could be... It's always a pisser when new filters foul, bit that's just them doing their job...

I forgot that your engine was out.. honestly, that leads me more to believe there is a bad connection somewhere.. those things happen on install..

Check your grounds.. closely.. check your power leads from alt and battery.. check harnesses, especially to the thunderbolt ignition.. get some dielectric grease and slap it on the fittings/plugs.. anything wired, check its seat.. its a six pack job is all, meaning the last one will be draining whilst you reseat your last connection..

aero3113

If I didn't have the issue before the engine was out I would say it might be a connection.Like I said, the boat ran great when I got it back from the shop. It only started to happen again today after about 4.5 hours on the filter.

212rowboat

Oh DANG!!! Reading comprehension is apparently something I lack.. :-)

If your tank is full of junk, you can thank your filters for protecting your engine.. swap em', friend..

If you gotta start with fresh fuel and get contaminants out, that's what you gotta do.. it may behoove you to figure out what's clogging them.. cut open the old one and see.. I'm curious, too.. also, though: a new filter does not restrict as a used one, which makes the pump work harder.. an aging pump loses pressure because its fighting.. they usually literally burn themselves out.. some OEM go so far as to submerge pumps (in fuel) to keep them cool.. it could still be your pump.

aero3113

LoL, I will try to replace the filter before we take the boat out again on Sunday.

brianluck

Good luck with the filter! Any possibility of water in the gas ?

aero3113

brianluck said:

Good luck with the filter! Any possibility of water in the gas ?

Could be, when I replace the filter I'm going to pour it into a container to see if any water was in it.

aero3113

I replaced my fuel filter today, it was on soooo tight (just put on when the pan was replaced). There were some black specs and what looks like a piece of plastic but no signs of water. When I went to leak check the new fuel filter is when I found the broken spark plug wire:) (see my oil pan post). Luckily it was caught before the spark caused an explosion! Hopefully the wire is what was causing the surging issue I had. Will let you know how she runs when we get back on Sunday.

Black_Diamond

Probably gasket parts and paint flecks.

212rowboat

Black_Diamond said:

Probably gasket parts and paint flecks.

Arrgh... concur, i do... 

say:  "thank you, mr. filter!"   :-) 

TikiHut2

Oy VEY. Did ya take that thing off with a pair of channel locks? Wow. That pic tells a tale of frustration indeed. Glad it caught the stuff it did. Changed mine last week and it was uber tight but no water or debris when I poured it into a pan.  :-bd Mike

aero3113

Perfect day out on the water and the boat ran GREAT!

brianluck

glad it was just a filter issue. i have bad luck with fuel in my area i like to change filters twice a year.