5.7 Fuel issues / Bad Mechanic

[Reming870]

Long story short: I hired the wrong mechanic and still have a problem.

2009 5.7 L Mercruiser / Throttle Body / Electric Fuel Pump

New water separator and fuel filter in pump replaced.

I cannot get fuel to the pump. If I manually fill the pump with fuel I can run the engine until the fuel pump runs out.

I can suck fuel from the tank all the way to the pump by hand with a hand pump, but cannot keep fuel at the pump to keep engine running.

Anti-syphon valve looks clean and clear. I have not pulled the whole tube out yet.

Any ideas what to do next?

 

[Reming870]

Re: 5.7 Fuel issues / Bad Mechanic

BTW: I have had the problem since de-winterizing. I have yet to get it to run proper since storage.

 

[Don S]

Re: 5.7 Fuel issues / Bad Mechanic

What is the serial number of your engine? Throttle body injection hasn't been used since 2000 or 2001.

 

[Reming870]

Re: 5.7 Fuel issues / Bad Mechanic

Don't know. Its 1.5 hrs away. I know it was new in 2008-2009 from the previous owner. It has a fuel rail with injection ports and an air intake butterfly damper off the flame arrestor. Fuel pump is mounted on the front of the engine starboard side. Maybe my terminology is wrong or it is an older engine than I thought.

 

[Don S]

Re: 5.7 Fuel issues / Bad Mechanic

Post a picture of the engine and fuel pump. Hard to say what could be wrong if we don't know what you have.

 

[Reming870]

Re: 5.7 Fuel issues / Bad Mechanic

Cant get there anytime soon to get the Model # and/or pics. I talked with the mechanic who put the engine in and he says it is an MPI. Also has guided to think it has a low pressure pump problem based upon symptoms.

Make sense?

 

[Don S]

Re: 5.7 Fuel issues / Bad Mechanic

I will have to agree with your mechanic, at least he knows what it is and how it's setup.

 

[frantically relaxing]

Re: 5.7 Fuel issues / Bad Mechanic

You have a 'throttle body', just not 'throttle body INJECTION'. No biggie. Soon as you said "fuel rail" MPI was a given

I'm not all that 'up' on injected boat engines, but I assume they have a fuel pressure regulator, and a fuel bypass/return line to the tank? If so, what would happen if the return line was plugged?

I remember YEARS ago my '84 Buick became extremely hard to start because the anti siphon valve in the fuel pump just let the all the fuel in the rail and gas lines go back to the tank. Took like 20 seconds for enough fuel to get back to the engine before it would start, and that was pushing the fuel FROM the tank. Again, not being 'up' on injected boat engines, do they have a second 'pusher' pump at the tank? If not, and the on-engine pump is expected to suck fuel from the tank, then the fuel lines must remain full, yes?