Volvo penta hot low pressure fuel pump

[dmanera]

Good evening!

I have a 1997 volvo penta 5.7 gsi and the low pressure pump is running very hot a idle, I just changed both the high and low pressure pumps because the high pressure pump was making noise and i did not want to take a chance so changed them both as a precaution, after changing both pumps I tested the motor at idle to ensure there were no gas leaks, I discovered the low pressure pump was running extremely hot, The voltage checked out ok, the anti siphon valve checked out ok, the fuel reservoir was clean and the float setting was correct, I changed the water fuel separator, I bench tested the old low pressure pump with water and when I restricted the water flow on the outlet tube the pump would get warm but not hot like in the boat, the fuel pressure on both the high and low pumps are within specification, the pump dose cool off when the rpm is raised because of the additional fuel running through it, although when it does get hot is starts to make noise as if it is going to fetch up, should the low pressure pump run all the while the engine is at idle? it appear that both high and low pumps are wired to the same relay is this correct? any help would be greatly appreciated.

thanks,
Dave

 

[24 Albemarle]

Re: Volvo penta hot low pressure fuel pump

I have same engine and my low pr. pump gets warm but not hot , I am sure you checked your fuel filter (clogged) have you checked your (tank) pick up tube as some have screens on them and will stop up. I think the low pn pump runs to fill the vapor tank and the high pr pulls from the tank to the tbi. Hence two relays.Maybe you can get a voltage draw reading to see if the pump is straining. The electrical y connector on the pump comes off,maybe check connection. But I'm not an expert, just a guy that has to fix his own crap.

 

[dmanera]

Re: Volvo penta hot low pressure fuel pump

I have checked the lines back to the tank and they are all clear, there is a float in the fuel reservoir that is connectend to the TB by a black hose and i am wondering if there is a switch that is controlled by vacuum that indicates the reservoir is full and shuts off the low pressure pump. Both high and low pumps appear to be wired to the same relay on the wiring diagram however, no one has been able to confirm if the low pressure pump should cycle on and this inculdes the mechaninc from the boatyard i purchased the boat.

 

[Albe24]

Re: Volvo penta hot low pressure fuel pump

I have the same set up... When my high PSI pump was making noise the low PSI pump was running warm also. After going over all the checks that you performed the noise was still there. I talked to a rep at Volvo and he said to check for any restriction of the cooling water going to and from the vapor separator, I found that the hose was partially plugged and was not getting a sufficient flow to cool the separator. After clearing the restriction, i have not had any fuel pump issues.

 

[Potomac-Bill]

Re: Volvo penta hot low pressure fuel pump

I have a late model Volvo 5.7 with a fuel pump running hot - a 2006 5.7 GXi-G. The wires supplying the power are also warm - so I suppose the pump is exceeding its normal current consumption. The hottest part is the smaller of the two pumps; which I believe is the high pressure pump - but I'm not sure. I don't see any reference to a "vapor separator" in the fuel system schematic for my engine. Does my fuel system have one? Would any of the diagnostics previously mentioned be different for my engine which has multi-port fuel injection instead of throttle body injection?

 

[npursuit]

Re: Volvo penta hot low pressure fuel pump

i have 1992 7.4 volvo penta had low pressure fuel pump changed about 8 hrs ago . went out about a mile sunday anchored for about an hour.got ready to leave engine cut off,checked fuel pump it was extremly hot and not working.noticed a few weeks back when key is on with engine off pump ran continuously is this normal.