Volvo 5.0 glx surging issue

Derklaw

Recruit
Joined
Jun 29, 2021
Messages
1
Ok so this problem has been persistent. New battery, new leads, new plugs and wires, new injectors, new distributor cap, new high pressure fuel pump, boat runs perfect in the driveway, take it on the water and put it under load and it gets about a half a Kilometer out and starts surging, drops down to idle and then when you chop the throttle it sputters and dies. I’m stumped at this point
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,701
Assuming GXI and not GIX
What is the motor serial number?
What is the fuel pressure when it starts to surge?
Is this a new to you boat or just a new problem?
 

Senior B

Petty Officer 1st Class
Joined
May 19, 2006
Messages
253
Sounds like a bad low pressure / boost fuel pump .. Says above that you replaced the high pressure pump. A bad boost pump, the boat will start and run, but when you take off it will quickly become fuel starved. Just a thought.
 

stouchton

Seaman
Joined
Feb 12, 2018
Messages
64
I am with Senior B on this.... and another clue will be if you high pressure pump is hot. The high pressure pump needs to be moving fuel to cool itself, and when there is no fuel in the tank fed by the low pressure pump it will starve and run hot - just experienced this myself. Oh - and that is why the small tank is water cooled - it is to cool the high pressure pump that would otherwise be recirculating hotter and hotter gas.

High pressure pump should run warm - I was surprised when mine was almost too hot to touch.
 
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