Volvo Penta 5,7 GXi-A loosing power

[Flipper700]

Hi everybody. I am a firsttimer here. But great site.

I have a flipper 700 cabin boat with a Volvo Penta 5,7 GXI-A engine.
For some time it has been going fine... but now there are problems.

No problem starting up, good sound from HP Pump 2 sec.
No Problem going for about 15 minut both over and under about 2200 rpm....

PROBLEM!!! when going from low speed to higher speed(over 2200 RPM?S) it suddenly Stalls. It loses power, and it sounds like it doesn?t get enough fuel.
It doesn?t always go out. If you go to idle.. and let it run for a couple of seconds.. it?s fine again. But same problem happens the moment u get over aprox. 2200 rpm?s.
Please someone Help....

Flipper

 

[Flipper700]

Re: Volvo Penta 5,7 GXi-A loosing power

By the way... have changed all fuel filters... tried external fuel tank... and cleaned the fuel Pump. The HP & LP pump seems to be pumping... could one or the other be faulty.. and maybe not generate enough pressure?

 

[Don S]

Re: Volvo Penta 5,7 GXi-A loosing power

By the way... have changed all fuel filters... tried external fuel tank... and cleaned the fuel Pump. The HP & LP pump seems to be pumping... could one or the other be faulty.. and maybe not generate enough pressure?

It's going to take a fuel pressure gauge to check it out.
You will also need a scan tool of some sort to check for fault codes and see what other possible problems it could have.
You are also going to need the OEM service manuals for your system.

 

[Flipper700]

Re: Volvo Penta 5,7 GXi-A loosing power

Hi have the manual already.... and have measured the pressure today HP P: 2,1 Bar LP P: 1,2 Bar. That should be a bit too high on the LP P, and with in normal for the HP P. But the problem didn?t show up while running with the gauges on. Will try again tomorrow. I dont have a scan tool, and i am not likely to get one... since the nearest dealer is a couple of thousand km away. Hopefully the gauge reading tomorrow will show something... Please if you have any other advises, do post a comment.

 

[Don S]

Re: Volvo Penta 5,7 GXi-A loosing power

Yea, your LP pump is double what it should be. Not sure why, but I would be looking at the VST to see if I could find the reason for the high pressure.
You may also want to consider a Rinda Tech Mate http://www.rinda.com/acro/prodlist.pdf
May not be as fast as having a laptop attached to your engine, but it can give you all the information if you take the time to access it. And it costs a lot less that a laptop, the software, and all the cables.

And Welcome to iboats. Don't recall seeing anyone from Greenland posting here before.

 

[Flipper700]

Re: Volvo Penta 5,7 GXi-A loosing power

Thanks.... it?s cold and full of ice and mosqitos for the time being... the more reason to get the boat going..... Less mosqitoes on the fiords.

I was just down checking... it seems that the knucklehead i bought the boat from, has put in a high pressure punmp instead of a low pressure pump. It reads "high pressure fuel pump, on the side of the pump." Is this a reasonable explanation for the acceleration stalling? Have been boating with this pump, with no problems since feb last year. I will look see if i can get one of those Tech Mates.... but it won?t be up here until 3-4 weeks...Sadly.

 

[Flipper700]

Re: Volvo Penta 5,7 GXi-A loosing power

News....

-The VST is okay... nop prob there.


We have now localized what happens... but not found out why... When we slowly accelerate up to 2400 rpm?s one of the Fuel injectors stops squirting, at just about 2400 Rpm`s... It is not the fuel injector, we have tried switching the cables around, and then its just the other fuel injector that stops. The power is continuosly on to the fuel injector, that we have measured. The 2 cables have the same powersuply, but has a groundwire, which is controlled by the (ECU)(MCU) right?
Could it be that the MCU/ECU is wasted? or does this type of engine have some kind of slow down mode... if any error is detected?
Has anybody experienced this kind of problem before??
WOW i Could use some expert help.....(Don where are u?) because a new MCU is not the cheapest thing...

 

[Flipper700]

Re: Volvo Penta 5,7 GXi-A loosing power

Okay....
Seems that we have found the error. It was going into Limb home mode(S.L.O.W). The oil pressure was fine, but when we checked the oil pressor sensor switch it was all rusty and ugly. When we removed the switch, we were able to run the engine above 2400- 2500 RPM?s. This means that the OIL pressure sensor switch was bad... right? the analog gauge shows fine pressure.