New to me boat new problem

[Bulabula78]

I just picked up a 1995 cruisers with twin 5,7 efi. Trial was great. Last couple times port engine stalls when low throttle and docking. The engine Cranks but won't fire up. If she did start then would shut off right way before I could put in gear. Tried throttling up and starting and that didn't help. If I wait a while 15 minutes it will fire up. I put probably 100 miles on her Saturday. When I got to my destination that is when port wouldn't fire. I noticed oil was very low, had a quart and added then next town picked up a couple quarts and added. Still had same problem. When I did get get to fire up I headed home cruising around 37 with no issues. Get to my dock area and do some shifting and port died out. Fresh tank of gas before trip.

Any help ideas appreciated.

 

[alldodge]

Howdy

Need engine serial number?

 

[Scott Danforth]

welcome aboard

as AllDodge mentioned, need serial numbers

this being a new to you boat:
check the contents of your fuel filters (replace the filters).
check fuel pressure
do all maintenance (engine and outdrives, including alignment)

 

[Bulabula78]

Will be at boat this Wednesday an can get numbers. Thank you

My last boat had the merc book, I wish I kept that book now. that was a 240 dancer 98
Anything else to quickly look for? I live 70 miles from my slip
Unfortunately no trailer to get her out of water. I had her shipped trailered from lacrosse wi to my slip in portage Indiana and local marinas are booked unti July.
Boat is a cruisers 3175 with alpha drive

 

[tpenfield]

:welcome:

Diagnosing problems on an EFI engine are a bit more difficult than the carburetor engine. I would cover the basics of fuel filter, but it sounds like it could be a fuel system pressure issue . . .

Serial number certainly needed to understand exactly what you have.

 

[Scott Danforth]

look up your manual here http://boatinfo.no/lib/library.html

 

[revkev6]

given that you said it was low on oil... I would be looking at a compression test as well. you may have low compression in one or more cylinder causing it to stall at idle.

 

[Bulabula78]

Port engine 0F292410
Sb engine. 0F289082

What does the serial numbers say besides engine make 5.7 efi?

Lot of info on this site and helpful people. Is this on tapatalk, can not find it?

Just went to the boat. Seems like oily water in bilge area. Felt oil on the port oil filter.

Port engine had 1.5 water hose that comes from top of engine that wraps to the underside with what looks to be checks or vacuums they have a side outlet with no hoses on one and other has short hose connected to nothing. My starboard engine I noticed that hose is connected to something.

 

[alldodge]

The serial number tells me you have throttle body injection, VST high pressure pump, mechanical low pressure pump, MEFI-1 ECM, Delco EST ignition and a knock module.

Since it wont start when using throttle only mode, going to need to check fuel pressure at the Throttle Body (TB). Going to need to get fitting to put inline at the TB. The Merc part number is 91-806901, but you should be able to find it on ebay or local auto parts place. Will also need a high pressure fuel gauge which can read to at least 60 psi. The gauge will attach to the shrader valve on the fitting.



The VST (Vapor Separation Tank) is filled with fuel by the low pressure pump. The tank has a float and needle seat similar to a carb. The low pump keeps the tank full and the high pump builds pressure to 30 psi for TBI.

 

[Bulabula78]

given that you said it was low on oil... I would be looking at a compression test as well. you may have low compression in one or more cylinder causing it to stall at idle.

Thank you, going to do this weekend.

 

[Bulabula78]

She started right up while at boat.

The serial number tells me you have throttle body injection, VST high pressure pump, mechanical low pressure pump, MEFI-1 ECM, Delco EST ignition and a knock module.

Since it wont start when using throttle only mode, going to need to check fuel pressure at the Throttle Body (TB). Going to need to get fitting to put inline at the TB. The Merc part number is 91-806901, but you should be able to find it on ebay or local auto parts place. Will also need a high pressure fuel gauge which can read to at least 60 psi. The gauge will attach to the shrader valve on the fitting.



The VST (Vapor Separation Tank) is filled with fuel by the low pressure pump. The tank has a float and needle seat similar to a carb. The low pump keeps the tank full and the high pump builds pressure to 30 psi for TBI.

 

[alldodge]

She started right up while at boat.

Yes, she starts right up, but when it doesn't start up, you said even using throttle only mode and it still will not start. If this is correct, then you have a fuel problem.

 

[Bulabula78]

Yes, she starts right up, but when it doesn't start up, you said even using throttle only mode and it still will not start. If this is correct, then you have a fuel problem.

Gotcha, is the fuel hose just like a Goodyear hose that I can put a tee inline? Is there a place to get the diagrams, prints for my engine? Would this be the low pressure mech pump issue possibly then?

 

[alldodge]

You can fit some kind of a Tee between the mechanical fuel pump and the VST, but you cannot use the same method between the VST and TB.

Low pressure pump = 4 to 7 psi
VST Pressure = 30 to 60 psi

 

[Bulabula78]

How often does the fuel water separator filter need to be changed? Annually? When removing the filter as long as the fuel pump is not engaged should be good, just let it drop into a bucket?

You can fit some kind of a Tee between the mechanical fuel pump and the VST, but you cannot use the same method between the VST and TB.

Low pressure pump = 4 to 7 psi
VST Pressure = 30 to 60 psi

 

[alldodge]

How often does the fuel water separator filter need to be changed? Annually? When removing the filter as long as the fuel pump is not engaged should be good, just let it drop into a bucket?

Depends on how much you boat. I change min every 3 seasons. Best thing to do with the filter is take it off trying not to spill to much. Put some rags around to collect drippings. Then pour the contents into a baggy or other clear container. If you see anything other then clean gas, let us know. Reinstall by filling the filter with clean gas before installing, and put a small amount of oil on the sealing gasket

The VST tank needs to be cleaned every 5 to 7 years IMO. To do this, you need to be careful removing the pump. It has a basket on the bottom and can get brittle. Don't try to remove it, just gently clean the basket screen. You will need a new o-ring for the top.

Here is your motor if you have a Bravo, BTW don't know if you have an Alpha or Bravo drive
http://www.mercruiserparts.com/5-7l-...350-v-8-1995-0

Here is the VST
http://www.mercruiserparts.com/bam/s...31871/1953/130

 

[Bulabula78]

Thank you, I have alpha though

Depends on how much you boat. I change min every 3 seasons. Best thing to do with the filter is take it off trying not to spill to much. Put some rags around to collect drippings. Then pour the contents into a baggy or other clear container. If you see anything other then clean gas, let us know. Reinstall by filling the filter with clean gas before installing, and put a small amount of oil on the sealing gasket

The VST tank needs to be cleaned every 5 to 7 years IMO. To do this, you need to be careful removing the pump. It has a basket on the bottom and can get brittle. Don't try to remove it, just gently clean the basket screen. You will need a new o-ring for the top.

Here is your motor if you have a Bravo, BTW don't know if you have an Alpha or Bravo drive
http://www.mercruiserparts.com/5-7l-...350-v-8-1995-0

Here is the VST
http://www.mercruiserparts.com/bam/s...31871/1953/130

 

[Bulabula78]

The links do not seem to work for me

Thank you for fixing links, I found my alpha from there

 

[Bulabula78]

Found
http://www.mercruiserparts.com/5-7l-bravo-efi-tbi-gm-350-v-8-1995-0

 

[alldodge]

Found
http://www.mercruiserparts.com/5-7l-bravo-efi-tbi-gm-350-v-8-1995-0

:thumb: