Engine pull for fuel pump replacement -- what other PM should I consider?

D

Dubliner

New Member
Jan 30, 2014
12
Wisconsin
Boat Info
'03 220 Sundeck
Engines
Merc 5.0 Alpha
I have read numerous posts and so finally will pose my question(s):

After what appeared to be a vapor lock on my Merc 5.0 MPI ('03 Sea Ray SD 220), my mechanic has recommended a new fuel pump -- after sea trial , fuel pressure not as good as when cold and pump sounded like it was "struggling". I am certain it is orig pump and don't believe engine has ever been pulled. NOTE: Boat did run fine on long 40 min runs (3,100 rpm ~26mph with light human load and 1/2 tank). It was only on restart that I experienced the problem one time (had to sit for 75 mins before it restarted).

Are there any preventive maintenance/replacement items I should do to take advantage of the labor time to remove the motor? I am sure there is a long list, so looking for the most likely things. Bar the block itself having a problem, I just don't want to have the downtime and expense of having the motor pulled again in the near future.

Also, even with a new pump, is vapor lock (I do not run ethanol gas) still possible? FL summer heat of course.

Thanks as always for the insight,
 
I had this problem on my Baja. If you are running manual fuel pump off the side of the block you need to look up Merc recommondations for this. They make a electric fuel pump that pluggs right in to the wiring harness. THis will take care of the problem. Hope you are not pulling motor to just replace fuel pump.
 
I have to ask the same question...why are you pulling a motor just for the pump?
 
I was wondering the same thing, as many deer involved, not to mention worrying about what else might get disturbed in the engine pull and reinstall. I was told that the pump is not accessible. This is a major marina and certified merc dealer that i do trust. I am not mechanically included, but am doing lots of reading.

I also am wondering even if fuel pump is original and "struggling", as the pressure gauge indicated (11 years, 307 hours, believed to have only run non-ethanol gas as it has been stored high and dry in marina it's whole life before I bought it), vapor lock is still a possibility even with a new pump. Is this a correct assumption?
 
He probably still has the older style - tucked in nice and tight behind the port side motor mount.

Ask your mechanic about the possibility of installing the check valve kit into the water intake hose (just before the t-stat). It keeps more water in the upper part of the engine, helping to keep it cool when it comes time to restart.

If there turns out to be no way to get that pump out (can't get to it through a combination of the battery compartment under the port-side seat and the topside?), then you might look into replacing (or at least giving some of these things a thorough going over)...

You can add to this list, this is just the first couple things I thought of:
-- Steering cable
-- oil pressure sensor
-- Trim switches
-- Coupler (unlikely to be bad, but absolutely worth the time to check it out)
-- Tune-up (plugs, wires, etc)
 
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why not leave the old pump in place and disconnect the fuel line and install an electric fuel pump in a more accessible location?.....i would think that would be MUCH cheaper and faster than pulling the engine......

cliff
 
Have you ever tried letting the motor idle for 3-5 minutes before turning it off? This worked for me on my 240SD which suffered from vapor lock. On my 210SD I had the check valve kit installed that Dennis (Lazy Daze) mentioned and that worked also.

I see no direct correlation between the fuel pump and vapor lock myself. Vapor lock (as far as I know) occurs in the fuel cooler and is a result of hot water back-flowing from the block into the cooler. Allowing the engine to cool down some by idling it before shut off or installing the back flow kit both help to keep the fuel cool enough that it should not vaporize.
 
HEXMER9TRACOOL_zps7f0aeee4.jpg
could plumb this into the water inlet as a fuel cooler too.
 
Thank you to all for the great insight! This forum is truly great in so many ways.

I did confirm it is the old style and is tucked away underneath Port side. I am going to go ahead and get her pulled, as I want to see what else might need addressing. The boat is in really great shape and I bought it for a fair value I believe with known maintenance history. I did expect some maintenance due to age to get it mechanically where it needs to be, so I will just chalk this up in my "budgeted" column:)

Enjoy the water and I will follow up after all is said and done with what else I end up doing during this pull. Cheers!
 
I replaced 3 fuel pumps on my boat in less than 200 hours. Theoriginal had over 1,000 hours. The first 2 were non OMC both failed the same way again the flat metal spring part at the diafram fateiged and broke. The last one put in was OEM. Non were made in the US.The last one is still working after 300 hours. If you replace the pump with the same type get the best you can so you do not land up like me.
 
For what it's worth, fuel pumps do not cause vapor lock, so you expect to have the no start issue after you change the pump. By Merc's own admission in their tech bulletin, there is no "cure" for vapor lock, only a masking of the problem, by installing a secondary fuel pump. The kit referred to earlier in this thread on Ebay is the thing. I struggled with vapor lock for 5 years before I came across the tech bulletin. Installed the secondary pumps, and haven't had an issue since.
 
Thank you! I have been reading about it and am considering an additional mod based on all of my learning.


370Dancer said:
For what it's worth, fuel pumps do not cause vapor lock, so you expect to have the no start issue after you change the pump. By Merc's own admission in their tech bulletin, there is no "cure" for vapor lock, only a masking of the problem, by installing a secondary fuel pump. The kit referred to earlier in this thread on Ebay is the thing. I struggled with vapor lock for 5 years before I came across the tech bulletin. Installed the secondary pumps, and haven't had an issue since.
Click to expand...
 
Quick update that hopefully helps others in the future.

Engine has been pulled and in addition to the fuel pump, we have replaced the oil pan (it had a pretty soft spot in it!) and we are also replacing the power steering cooler (PS had some water in it). I am basically having the tech go through the entire lower end that is out of sight before it goes back in. A few herd will hopefully pay off and prevent some failures in the future.

Will update again when all is said and done. Cheers!
 
Sis u think about putting in an oil drain tube in the drain plug home so u can actually drain all the oil during oil changes and not have to suck it out and leave excess oil in the pan.
 
CliffA said:
why not leave the old pump in place and disconnect the fuel line and install an electric fuel pump in a more accessible location?.....i would think that would be MUCH cheaper and faster than pulling the engine......

cliff
Click to expand...
I'm having the same issue and your suggestion could be a godsend!! An y add'l info would be tremendously appreciated! Part numbers, pictures anything that could re3leive some of the fear and frustration! TIA! al
 
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