Mercruiser 140: Fuel Issue: Fork in the Road

[Chef Shawn]

OK Forum, Work your magic...lol

1986 Mercruiser 140, first few runs this year were great, 4200 WOT. Next week about 3200, then surge and cut out. Next week 2000, surge and cut out. This week, crap-ola. Will start and idle, but if I even THINK about touching the throttle, dies. New fuel filters (at carb and fuel pump). So went the the old posts, couldn't really find anything solid, but I have a couple of thoughts if someone could push me in the right direction.

1. When I was stranded on the lake, I pulled the filter from the fuel pump (Carter, on the side of the block), which I believe should have been full of fuel, it wasn't.
2. I disconnected the fuel line from tank to pump and held it down low in the bilge, no fuel came out.
3. I blew INTO the fuel line (toward tank) and could hear gurgling, but still no flow toward pump.
3. Yes I topped off the tank and added a bottle of Seafoam BEFORE this last trip, but I have also been adding Seafoam almost every fill-up just to keep things clean.

So did all of my additives clean my tank and that junk is clogging my fuel pick-up line to the fuel pump?

I DID read I could pull the pick-up line, eliminate the screen and just add an in-line fuel/water separator which would collect most of the big junk before it had a chance to reach the filters.

Thoughts?

Thank you in advance.

 

[Chef Shawn]

Re: Mercruiser 140: Fuel Issue: Fork in the Road

OK, 83 views and no replies. I got this.....Where the heck is Don S. when I need him. I rubbed my crusty lantern....

 

[Eric 3.7LX Alpha 1]

Re: Mercruiser 140: Fuel Issue: Fork in the Road

What did the fuel filters look like when you changed them?

I think it's a great idea to add the fuel water separator in there too.

 

[PeterB26]

Re: Mercruiser 140: Fuel Issue: Fork in the Road

Sounds like a bad fuel pump. Marine fuel pumps have dual diaphrams and are designed to fail differently than auto fuel pumps.

Water separating fuel filters do not work with ehtanol gas. The water doesn't sink to the bottom of the gas until phase separation occurs. By then you have bigger problems.

Just putting the end of the fuel line down low in the bilge won't cause fuel to come out of the line unless you started a siphon. If the fuel line was lready dry, just putting the end of it lower thant he fuel in the tank does nothing.

You can get intermittent clogging of the pick up.

You can add too much of something to anything regardless of what people say. Fresh gas is your best bet and stop filling up with SeaFoam or any other additive unless you have a good reason to use it, and then use it in moderation.

Peter

 

[Chef Shawn]

Re: Mercruiser 140: Fuel Issue: Fork in the Road

Both fuel filters were clean, less than a month on them. Pulled the pick-up connecting hose from the tank last night, it was clean, but destroyed the hose trying to get it off, so will have to replace.

It IS a 30 year old fuel pump, might as well swap that out too and see what happens.

And as for the separating filter, I wasn't worried so much about water as I was chunks of crap from the tank, was told it would catch the big junk before it hit the filters, and was easier to clean.

 

[Chef Shawn]

Re: Mercruiser 140: Fuel Issue: Fork in the Road

Update: Tank was fine. Pump was fine. Hoses fine. Didn't watch the helping son close enough, carb filter put in backwards. Sigh....

 

[LagunaBlue]

Re: Mercruiser 140: Fuel Issue: Fork in the Road

Update: Tank was fine. Pump was fine. Hoses fine. Didn't watch the helping son close enough, carb filter put in backwards. Sigh....

Amazing how much trouble that little $1.99 filter can cause if not installed correctly. Glad your back underway