2005 verado 275 will not run after FSM repair

[Ragtag187]

Join Date
Mar 2019
Location
Port Saint Lucie, FL
Posts
3
Verado 275 will not idle
So I just got my powerhead rebuilt. Motor ran well throughout the breaking in process. Seemed like I had a fuel issue because when I open the throttle to get on a plane it started to break up and after 4500 rpm while planes I would have to finesse the throttle to get it up to full speed. I replaced everthing in the FSM. Pumps and float are working properly and the hose inside is perfect. Now I cannot keep an idle when starting. It will run for about 5 to 10 second then break up and stall. Any ideas what could be causing this? It ran fine before I worked on the FSM. There is no air in the system that I can tell and I am getting 45 to 55 psi on the fuel rail. Is there a procedure for checking or cleaning out the VST?
Serial number 1B151685
Smart craft equipped
21p prop
45-55 psi on fuel rail
Engine temp never hotter than 145
Oil pressure 35-45
Engine temp an oil based on when it was running last.
Pumps and float just replaced.
Reference hose in FSM inspected and good

It ran good before I changed the FSM internals. Now it runs for 5 seconds and stalls

[vicsservice]

You need somebody to monitor it with a computer while trying to run so they can monitor the float switch and vent, it sounds like you have air trapped in the fuel system? what was the cause of the powerhead failure?

[Ragtag187]

It was overheated by the previous owner and cracked the block

[Ragtag187]

I feel that there is air in the system also other than the two Schrader valves one being on the fuel rail and the other being between the canisters. I dont know of any other way to purge it

[davidwademarine]

Go back and double check your work. Could be as simple as a quick-connect hose fitting that didn’t get seated properly or even crossed with another.

[Ragtag187]

I have had it apart a couple more times since this issue began. Everything is as it should be. Is there a proper bleeding procedure that I may have mucked up?

[EuropeanAM]

You need somebody to monitor it with a computer while trying to run so they can monitor the float switch and vent, it sounds like you have air trapped in the fuel system? what was the cause of the powerhead failure?

Can't monitor on this engine model- has to be done with a Vacuum Gauge (installed in the fuel inlet line). Relay driven fuel pump started with July, 2005 production (these early ones are the odd-ball).

There is no bleeding procedure for the FSM- other than to prime a very small amount of fuel into the system (approximately 8 oz) so the pumps are not dry.

It would be beneficial to have a Computer Diagnostic System recording of the engine when this is occurring, which allows the recording to be played back later (over and over if necessary) while monitoring data.

Run History and Freeze Frame (Fault) History would also be helpful. Be happy to review those for you, if necessary.

Note: Did you replace the block, complete powerhead, or ??? Very important question, as this is a Gen-1 (very early) engine.

Also be sure to check the boot and the MAP sensor (as well as the Crank position sensor). Both are potential problem points that can potentially cause symptoms similar to yours.

[Ragtag187]

The powerhead was replaced. I wound up dropping it off to a local Mercury Certified Mechanic. With my limited knowledge of verados and not possessing the proper equipment for diagnostics. I would have to guess that something has gone wrong with the crank position sensor or the key way on the flywheel causing the timing to be impossible to be adjusted by the computer. I'll let you guys know what the verdict is once the mechanic has completed the diagnostic procedure.

[EuropeanAM]

As far as being out of time- keep in mind that it is possible for the CAMS to be out of time, too.

[Ragtag187]

As far as being out of time- keep in mind that it is possible for the CAMS to be out of time, too.

I am hoping that isnt the case. Otherwise the powerhead will need to come back off.

[Ragtag187]

When we were breaking it in the first hour. I heard a metallic clunk and thought I had run over something. I was dead center of the channel. Upon returning to the boat ramp I saw a partially submerged palm tree in the area that happened. We were running at about 1500 RPMs. So I am just speculating here when I say that the momentum of the flywheel could have possibly sheared the key way pin off and has gotten further out of time as we continued the break in procedure. I inspected the lower unit and saw no visible damage. But after speaking with another verado mechanic via telephone. He suggested that an abrupt stop of that nature has been know to shear off the key way pin and render the crank position sensor useless

[vicsservice]

Hitting objects can knock the timing off... so Don is it that g3 can't see the float switch?

[EuropeanAM]

Yes- on most Verado models built prior to July 1, 2005. Later models utilized a relay-driven fuel pump (and lift pump switch monitoring)... which is what you're thinking of. That first year was an exception.