Mariner 60hp 4 stroke EFI 2003

[dreamfish]

After about 20 minutes of running, engine starts to die. I can keep it running normally by pumping bulb almost constantly. Have tried different fuel tanks, new fuel line and renewed both fuel filters. Replaced mechanical fuel pump twice, thinking maybe first fuel pump was faulty, have also ran fuel line straight to fuel pump to rule out sucking air but problem is still there. Wondering if anyone has had same problem or has any idea what is causing this please.

[Nos4r2]

Have you tried a different black box?

[Downhilldai]

Perhaps the float valve in the Vapour Separating Tank needs looking at?

[Damien.]

I would be inclined to look at the electric fuel pump.

It sounds like the pump is failing to supply the engine with sufficient fuel pressure, which you are compensating when priming the bulb.

Can you put your hands on a fuel pressure gauge ?

Also a complete stab in the dark her but can you simulate the problem while stationary ? If so, measure voltage at the pump when the engine is dying.

[Downhilldai]

Originally Posted by Damien.

I would be inclined to look at the electric fuel pump.

It sounds like the pump is failing to supply the engine with sufficient fuel pressure, which you are compensating when priming the bulb.

I wondered about that, but thought the electric pump is probably ok as the motor runs for 20 minutes before the symptoms set in.

[Damien.]

True, but not worth ruling out.

Ideally we could do with some fuel pressures and voltages otherwise we could be reeling off possible causes all night long.



Alot of the time this type of problem is down to a vent on the tank or blocked pick up but it seems the OP has eliminated the before engine supply.

[Downhilldai]

Originally Posted by Damien.

True, but not worth ruling out.

Ideally we could do with some fuel pressures and voltages otherwise we could be reeling off possible causes all night long.



Alot of the time this type of problem is down to a vent on the tank or blocked pick up but it seems the OP has eliminated the before engine supply.

Yep, armchair diagnosis from 200 miles away.

[Red Fox]

Get it to an authorised service dealer and tell them. They will plug it in to the computer and sort the fault in no time.

[dreamfish]

Thank you all for your replies. I am now on my third mechanic with this engine, (he is looking at it today,hopefully!) the vapour seperator tank has been stripped and cleaned. it has been connected to computer and showed no faults. I have been told fuel pressures are ok. Nos4r2 what is the black box?

[Turbodiesel]

I dont think the computer will find a fault. i would get your nearest dealer to put a fuel pressure gauge on it, and see whats going on, check if your maintaining fuel pressure. The Laptop wont read fuel pressure.