Mercruiser 3.0 Fuel Issues

[cubajorge_2008]

I changed the check valve going to the tank. Changed the carb and the fuel pump and added a clear inline fuel filter. I notice that the filter always have air on it at the beggining. After a while the filter gets filled all the way and will stay full. However when restaring the engine again minutes later when it cold. The clear fuel filter empties half way. Isnt suppose to always stay full?? What can cause this issue?

 

[H20Rat]

If it is full and then empties, it is either coming in through a leak, or a faulty one-way. (not all leaks will leak fuel, it is entirely possible to only leak air in, and not fuel out)

Also, what type of filter? Not all filters are certified for use on an inboard, and it could be a fire risk.

 

[cubajorge_2008]

The ones that they sell on west marine stores. They are clear plastic filters. I been having this issue and havent figure out whats wrong yet. It is like the fuel pump will pump air when the first start up happens .

 

[alldodge]

So long as the carb fuel bowl is full there is no issue.

No where is it allowed to have clear/see thru anything on a I/O except for testing

 

[QBhoy]

Agree with AD. The filter you’ve put on is no good for that engine.
I’d maybe ask to rewind a little. What was the issue symptoms that made you do this in the first place ?

 

[cubajorge_2008]

Agree with AD. The filter you’ve put on is no good for that engine.
I’d maybe ask to rewind a little. What was the issue symptoms that made you do this in the first place ?

I always thought it was good to have an inline filter for extra filtering. I been having hard start ups and while searching the engine i realize the fuel filter is always half full when is cold. Eventually it will fill up when it gets warm and rev up a little. But on the next start up while the clear filter is still showing full and i attempt to start it i notice it becomes half full again… could it be that the pump is sending air on the first pump?

 

[QBhoy]

I always thought it was good to have an inline filter for extra filtering. I been having hard start ups and while searching the engine i realize the fuel filter is always half full when is cold. Eventually it will fill up when it gets warm and rev up a little. But on the next start up while the clear filter is still showing full and i attempt to start it i notice it becomes half full again… could it be that the pump is sending air on the first pump?

You could have one of the proper water separating ones fitted, I suppose. They go on the bulkhead in line with the tank

 

[Grub54891]

Is this filter before the pump or after?? Regardless it's not coast guard approved. You should have a spin on filter bulkhead mounted before the pump. The pump on a 3.0 has a filter in it already, so another one is really not needed except for water separating purposes. How about a pic of your setup?

 

[alldodge]

The filter that came with the boat is part of the fuel pump guessing no serial number). If pump was changed to an automotive one, then this would explain the inline. My original comment was about clear and/or see thru, this type is not allowed only metal

 

[poconojoe]

We see it an awful lot where automotive non-marine parts are used on marine engines. It's due to ignorance and not intentional.
Hopefully people that come here are enlightened and realize that if you use an automotive starter, distributor, fuel pump/filter, etc, etc... that's not marine approved, you can cause harm or even death.
Remember...there's no place to run when a boat catches fire. If you're lucky, you and your passengers have time to jump overboard.

 

[QBhoy]

The fact is that if it’s a marine 3.0. As said, it has a filter in the fuel pump. And many many many of them are in use all around the world, just as they are. But if you were fussy, a marine water separating filter is a good idea. But I’d still ask why you thought you needed a in line filter originally. What was she doing or not doing to make you fit one. All the best.

 

[cubajorge_2008]

Is this filter before the pump or after?? Regardless it's not coast guard approved. You should have a spin on filter bulkhead mounted before the pump. The pump on a 3.0 has a filter in it already, so another one is really not needed except for water separating purposes. How about a pic of your setup?

It is between the carb and the pump

 

[cubajorge_2008]

The fact is that if it’s a marine 3.0. As said, it has a filter in the fuel pump. And many many many of them are in use all around the world, just as they are. But if you were fussy, a marine water separating filter is a good idea. But I’d still ask why you thought you needed a in line filter originally. What was she doing or not doing to make you fit one. All the best.

For me was just ignorance . I will add the water fuel separator and remove the clear one. The main reason i added was to see why i was having hard start ups and is when i discover that when the engine starts at first the clear filter gets filled with air on the first pump of the fuel pump but have no idea whats causing it

 

[cubajorge_2008]

We see it an awful lot where automotive non-marine parts are used on marine engines. It's due to ignorance and not intentional.
Hopefully people that come here are enlightened and realize that if you use an automotive starter, distributor, fuel pump/filter, etc, etc... that's not marine approved, you can cause harm or even death.
Remember...there's no place to run when a boat catches fire. If you're lucky, you and your passengers have time to jump overboard.

I bought the fuel pump of amazon and supposely was marine grade

 

[cubajorge_2008]

The filter that came with the boat is part of the fuel pump guessing no serial number). If pump was changed to an automotive one, then this would explain the inline. My original comment was about clear and/or see thru, this type is not allowed only metal

Got it. I will get that fix

 

[cubajorge_2008]

Before you guys said anything Im using a fuel regulator but only until i get the fuel pump
Original gasket that should arrive next week wednesday. The after market fuel pump seems to pump to much pressure around 9psi. Moreover, as you can see on the pic the clear fuel filter is half full and it happens everytime on start up. Causing my start up to be rough and longer to warm up

 

[alldodge]

Hard starts are because of other things like the choke not set correctly, carb leaking, spark. Once the carb gets fuel it should run unless there is an issue. If the throttle can be pumped when cold, then there is gas, so then its the choke or other

 

[cubajorge_2008]

Hard starts are because of other things like the choke not set correctly, carb leaking, spark. Once the carb gets fuel it should run unless there is an issue. If the throttle can be pumped when cold, then there is gas, so then its the choke or other

Well to be honest i got the carb on amazon brand new and opened up and set it correctly but i do notice that the choke makes it to rich and dump alot of gas in there making it smoke on cold start. My old carb didnt do that. What can i do about it?

 

[alldodge]

Most likely the float needs to be reset. The bouncing around can do that to it in transit

 

[Grub54891]

Electric choke, Loosen the cap on the choke, move it open one notch, tighten cover. Test the results.