225 promax shutting off at speed

[rudecraig]

this happened twice this past weekend.225 promax running about 5k rpms just shut off like someone turned the key off.this is a twin engine boat so i stayed on plane with the other engine.took it out of gear and it started right up.like i said it happened twice and this was during a poker run so the motor had been running a few hrs.any idea's what i should be looking at?

[HStream1]

this happened twice this past weekend.225 promax running about 5k rpms just shut off like someone turned the key off.this is a twin engine boat so i stayed on plane with the other engine.took it out of gear and it started right up.like i said it happened twice and this was during a poker run so the motor had been running a few hrs.any idea's what i should be looking at?

Not to say this is your problem but, I had a similar issue and it was flooding injectors. But mine took a few minutes to restart. Had them serviced by Brucato solved. I also located some grounds that needed cleaning.

[TheRickster]

Fuel pump driver circuit in the ECU notorious for intermittant shut offs..Driver overheats and kills the fuel pump. Turn the key off and it will crank back up immediately.. I normally remove the ecu wires from the fuel pump and wire it relayed to 12V key on..

Rick

[Tony Brucato]

It could be that you need to rebuild the low pressure fuel pump on the side of the block. When the diphram gets worn or torn, it doesn't keep up with the volume that the high pressure pump uses at high RPM. Basically it makes the VST pump run out of gas. It will ussually start up right away.

[Hydro BP]

Believe it or not but mine done the same thing and it turned out to be a bad switch box. I replaced everything posible and after I replaced the switch boxes it quit shutting down and boy was I glad cause it is a bad feeling shutting down at 90 plus :eek:

[rudecraig]

well i started looking at stuff last night.don't know if this could do it but i found my gps speedo wires that go to the tattle tale recall/erase switch fell off and looks like they may have been touching each other.gonna fix those and clean all other connections 1st.then start swapping parts with the other motor

[Steve Pope]

Have had 3 different problems causing switch off type shutdowns with instant restarts.
1... Faulty voltage regulators overcharging batteries causing ecu to shut down fuel pump.Cranking engine drops battery voltage sufficiently to allow ecu to run normally.Once this fault appears it usually re occurs again within 10-15 minutes.
2...High current draw fuel pump. Same symptoms as above but usually ok below a certain rpm eg ok under 4000 and plays up above.
3....Faulty fuel pump driver in ecu. Usually a random shutdown.

Running the fuel pump seperately from the ecu may make the problem of stopping go away but you will not know what the true fault is. Popey