could use some help

[Lloyd s]

Ive been working on a future x-friends boat but the problem keeps illuding me,I have checked every electrical componet on the engine and all appears well,i then checked fuel pressure and its between 34 to 35 psi so i replaced the fuel pump and still 35psi.would anyone have a guess,i'm thinking fuel regulator but the symptoms of reg.failure doesn't match! Boat runs W.O.T. for roughly 45sec to a min then shuts down as if the key was turned off,cranks right back up then repetes! HELP!

 

[redjmp]

Re: could use some help

How about you start off by telling us what year and model of motor you have?

 

[Lloyd s]

Re: could use some help

my appologies, 2000 model Mercury225 EFI

 

[jerryjerry05]

Re: could use some help

Always include model,serial# and hp.
Makes it easier to get specs.
According to the specs I found for that motor(need serial#).
The fuel pressure should be 41-45#The mechanical pump pressure at WOT is max 10# Idle 2-3#
I have a 97/225 EFI The motor ran bad. Checked EVERYTHING,it all pointed towards the regulator.The local mechanic (stayed over 2 months here)said they NEVER go bad.The traveling Mercury tech said they NEVER go bad.The guys in Delaware at one of the better shops said they NEVER go bad.Guess what it was bad.
It took almost a year to figure it out.Replace the reg with a used one and off I went!!! Then a week later something else went wrong and now I'm selling it for parts.
Post the ser# and I'll make sure the specs are right.J

 

[Lloyd s]

Re: could use some help

Thanx for the input it is very much appreciated,I changed out the regulator today and same thing 35psi.in the morning im going to check the rest of the hoses on engine .Will letcha know,thanx bro.

 

[jeffersondodson561]

Re: could use some help

Put a jumper wire to the negative side of the fuel pump and see if conditions improve, the ECU primes the fuel rail before starting for a few seconds and then once started is supposed to supply a ground for continous running. If the wire improves your condition, check every possible wire going to and coming out of ECU, if everything checks out ECU is possibly bad.

 

[Faztbullet]

Re: could use some help

Your fuel pressure is fine, manual states:
Line Pressure @ Injectors 34 psi -- 36 psi (234kPa -- 248kPa)
If jumpering the pump does not help ,attach a timing light with trigger taped closed and test run to see if spark drop when it dies. If so check the wiring ,CDM's and ignition ECU. Also check the voltage at battery if it drops below 9.5vdc while running the fuel pump will drop out.If so check alternator.