04- 40 Merc EFI fuel problem

[Toddage]

I saw something similar to this on another thread but there was no resolution to it.

I have changed the pumps, filter and water seperator, new gas.

When I run at full throttle for 3 minutes it shuts down, but does not actually stop just barely runs then it catches up. I immediately run it again after it picks up and then it shuts down after a minute and keeps doing that. The water seperator is running out of fuel but I cannot find a leak or anywhere air could be getting in(loose connection) I have blown out all the lines. Now I am wondering if the pressure regulator could be causing this basically because I am out of ideas. Is this possible?

 

[Toddage]

Re: 04- 40 Merc EFI fuel problem

I forgot to mention theat it runs for a lot longer at quarter to half throttle.The water seperator no longer runs short of gas after I trimmed some hose ends to eliminate any possible air problems(no help). I then began to think temperature problems and removed the thermostat because after it would shut off I could hear a noise in that general area(restricted water flow type sound) nothing. I am getting no warning beeps to help me out. I guess I have to bite the bullet and take her in or find a meter and do the tests in the service manual. 3 hr. drive and long wait to nearest service place is why I have been trying to fix it myself. Any ideas where I should start with the electrical troubleshooting.

 

[Coloradolakeboy]

Re: 04- 40 Merc EFI fuel problem

Vacuum meters are available at NAPA auto parts stores. I paid 30 bucks for mine. Get some clear hose and check for air while your at it.