Volvo Penta 7.4 GI

[Sunnyide]

Hello community, i’ve been having power issues with this engine. We already did
spark plugs, rotor, fuel filter, injectors and now we are waiting for the distributor to try a new one. Its on a 2000 Cobalt and I’m guessing it’s the only engine it have had. Any other guessing about what it could be?
thank you so much guys

 

[alldodge]

Welcome

Is this a new to you boat or is this something that just started?

The first things is check fuel pressure of the high and low pressure pumps
HP pump should be 39 +/- 3 psi
LP pump depends on which GI version, EF 8 +/- 4 psi, HU to WT 5 +/- 3 psi

 

[Sunnyide]

We did checked the fuel pressure and it was right. I don’t know if it was like this last season but the other thing is that the boat also have only 200 hours which is super low considering that its a 20+ years old boat.

 

[alldodge]

Take the fuel filter off and dump the contents into a clear container, there should be noting except clear and clear gas

 

[ChooChooSnakeMan]

I don't know if the infamous fuel cell paint issues were present in 2000 or perhaps your boat got a replacement fuel cell made when they painted the inside of the cells! I know, who could have thought that was a good plan but nonetheless it has been a problem for many years. My 2011 8.1 Gi-J had the problem. One way to tell is to unscrew your fuel filter that screws onto the fuel cell. Look around the inside around the gasket. If you see small black flecks then you likely have the paint issue. It clogs up everything and I've read that in an extreme case it can plug an injector and turn that cylinder into a grenade:-( Like I said, maybe if your fuel cell is original to a 2000 year engine it doesn't have the paint problem. Taking the fuel filter off and looking is an easy check.