Mercruiser fuel problem.

Hey everyone our boat is having a bit of trouble lately especially this morning at hillarys it was idling then just cut out. It is loosing fuel for some reason but we cant work out why. We have just had a new tank made fitted all new lines and replaced all the filters. It has a primer bulb inline to get fuel to the motor but after running a while it goes soft and cuts outs. It is a 5.0L mercruiser MPI 2008 model. Trying to get it realiable for easter as we have a mooring booked for 5 days in bunbury. If we cant figure out why we might just plumb in a lift pump. Any help much appreciated. Cheers

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Dinkum Auto Electrical A/C & Mechanical Unit 10/16 Kent way Malaga 0438755754 Also Mobile

Open 7 days except when we are fishn For all your auto electrical needs


reevesie90's picture

Posts: 62

Date Joined: 30/12/12

tank

Sun, 2013-03-17 18:41

 hi mate has the tank got a breather? if not it will suck as much out as possible before there is no air left in the tank, it would be like sucking on a straw with your finger on the end

kempy's picture

Posts: 810

Date Joined: 28/05/09

I wish it was something

Sun, 2013-03-17 19:19

I wish it was something simply like that so we ran it without the fuel sender in so it could breath.

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Dinkum Auto Electrical A/C & Mechanical Unit 10/16 Kent way Malaga 0438755754 Also Mobile

Open 7 days except when we are fishn For all your auto electrical needs

carnarvonite's picture

Posts: 8673

Date Joined: 24/07/07

Pick up

Sun, 2013-03-17 18:41

Sounds like you may have a problem with the pick up inside the tank or its leaking air into the line somewhere.

 

Using the bulb to prime it creates greater suction than the leak allowing the fuel to be pulled up but once the engine is running there is less vacuum and then more air being sucked in.

kempy's picture

Posts: 810

Date Joined: 28/05/09

This is what we also thought

Sun, 2013-03-17 19:21

This is what we also thought and spent hours looking for where it could be but we pretty much ruled it out as we ran a line from where the fuel sender goes in straight to the filter bowl on the engine.

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Dinkum Auto Electrical A/C & Mechanical Unit 10/16 Kent way Malaga 0438755754 Also Mobile

Open 7 days except when we are fishn For all your auto electrical needs

shonky's picture

Posts: 203

Date Joined: 22/04/12

Filters

Tue, 2013-03-19 18:13

 Did you fit the filters before or after this problem occurred,could be shit left over from the tank build. If not the fuel pump might be stuffed.

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This habit is getting expensive!

kempy's picture

Posts: 810

Date Joined: 28/05/09

Just replaced all 3 filters

Wed, 2013-03-20 06:39

Just replaced all 3 filters and still the same.

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Dinkum Auto Electrical A/C & Mechanical Unit 10/16 Kent way Malaga 0438755754 Also Mobile

Open 7 days except when we are fishn For all your auto electrical needs

Posts: 408

Date Joined: 23/11/09

Question

Tue, 2013-03-19 19:23

 I may be living up to my name, but if it is a mpi why is there a primer bulb. doesnt it have a fuel pump ?

 

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kempy's picture

Posts: 810

Date Joined: 28/05/09

It is fuel injected but the

Wed, 2013-03-20 06:39

It is fuel injected but the pump is on the motor so it needs to be siphon fed and if it gets a blockage or air in the line etc it wont bring the fuel up.

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Dinkum Auto Electrical A/C & Mechanical Unit 10/16 Kent way Malaga 0438755754 Also Mobile

Open 7 days except when we are fishn For all your auto electrical needs

carnarvonite's picture

Posts: 8673

Date Joined: 24/07/07

Fitting

Wed, 2013-03-20 06:49

Going by your comments , all fuel lines and filters have been replaced from the pump through to the tank, have you had a look at the actual fitting on the fuel pump? Could be leaking air through the threads or not seating properly.

Fitting an electric fuel pump could help but doesn't solve the original problem.

kempy's picture

Posts: 810

Date Joined: 28/05/09

The pump is incorporated into

Wed, 2013-03-20 08:57

The pump is incorporated into the filter all as one unit that is mounted on the side of the engine> there is no actual piping from the filter to the pump in runs through a galleryl in the cast housing.

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Dinkum Auto Electrical A/C & Mechanical Unit 10/16 Kent way Malaga 0438755754 Also Mobile

Open 7 days except when we are fishn For all your auto electrical needs

Posts: 15

Date Joined: 28/06/10

Mercruiser

Wed, 2013-03-20 09:02

Call Frank at Matich Marine, head mechanic and Mercruiser guru