Help with Caravelle 209 Volvo 5.0 PFES

[Dhassan76]

Good morning all! I've owned this Caravell for about 2.5 years. When I first got it, it would not go above 3500rpms.. diagnosed a ball fuel pump and replaced it. Granted it was not an OEM pump, but rather a knock-off. The boat has ran well up until now. It has about 450hrs on it and has been well maintained. I changed the fluid and filters every season, or about 75hrs. I used fuel additive every tank.. as it is fuel injected and I'm trying to keep the system as clean as possible.
I started to notice this 2 trips ago, but definately it happened last outing. It was struggling to get on power. When pulling a tube, if you just matted the throttle it would essentially just bog.. never getting into the power band of the enigne. If I "feathered" the throttle back and forth it would come on much better and get on power. Once up on power it did "ok".. but I've also noticed that just cruising around it seemed like the power and rpms would fluctuate.
Not sure why you would have to feather the throttle of an FI engine. I would also think if there was mechanical damage (engine wear, scored cylinder, etc..) that it would never really get on power, or just be low on power in general. But like I mentioned if I feather the throttle back and forth it seems like it will start to rip like normal.
So this is not the same symptoms I had with the previous bad pump. Back then it simply wouldn't go about 3500rpms. Now it will, but it doesn't like to be given hard throttle fast. Other than that it seems to be running ok. No noises, easy startup, no smoke, etc..
Any ideas? I believe this is the 5.0 PEFS Volvo Penta! Thanks all!

 

[Dhassan76]

Well I'm hoping I found the problem. I pulled the fuel/water filter to check for water or just analyze the fuel a little. Nothing notable there, but I noticed that the two lines that run from the high pressure pump side were very loose.. could easily turn by hand and could wiggle the line significantly. I don't think it was causing the fuel to leak, but I'm hoping it was causing air to get in the system.
Probably wishful thinking, but I don't know what to look at next.

 

[itsathepete]

If it was the inlet side of the pump it could be the problem but if it was the output, it would be leaking. Check the fuel pressure. I believe it should be 30psi

 

[Dhassan76]

Ok throwing this back on top. Fix above didn't work.
I pulled plugs and they look "normal" to me.. all plugs have a good tan color. Did compression check and got 155-170 on all cylinders.. with each getting there in about 5 revolutions. Did fuel pressure check again, both at idle and under load and when it is not acting right. The low side holds 6-8 and the high side 28-30. No real movement.
Took spark arrestor off and watch injectors. When moved to WOT, it does appear that the right injector is spraying almost 2x that of the left. So perhaps I've got an injector issue? It just kinda bogs.. but doesn't really bog, it just doesn't seem to want to get RPMs up and plane. If I pull back and forth on the throttle I can get it to come up a little better, but once I am up and running the throttle is not steady.. I have continually manipulate the throttle. It also just seems low on power. WOT it just doesn't want to move like it used to.
The only other thing I noticed is the engine/coolant temp. According to the gage it hovers around 140.. that seems kinda low. Not sure what parts to throw at it now.

 

[itsathepete]

If you are seeing the injectors not spraying evenly, it could be a bad injector or it could be a blockage in the throttle body. Remove throttle body and injectors. Disassemble as much as you dare and thoroughly clean it. Make sure all fuel passages are open, spraying carb/throttle body cleaner through them and ensure you get good flow from the fuel inlet all the way to the injector ports. Inspect the injectors for any debris on the inlet side and clean if possible. If this doesn't help, it does sound like a bad or plugged injector. As a quick check, you could swap the positions of the injectors. If the same injector sprays poorly no matter the position, it is an injector problem. If all injectors spray poorly in a certain position, it is the throttle body or possibly an electrical problem not triggering the injectors properly.

 

[alldodge]

The PEFS is good to know but the G(and letter) is more important. Serial numbers are best. Noting mentioning watching the injectors indicates TBI so probably a Gi

Compression is high but that could be your gauge, good thing is they are even. Does the fuel pressure stay around 30psi as RPM is increased?

 

[Dhassan76]

Yeah 5.0 Gi PEFS, 2000, about 500hrs. I also did new cap, rotor. Below is link to video I uploaded on how the injectors looked. Yes, while this test was taking place fuel pressure remained constant at 28-30 psi.

 

[Dhassan76]

And for what it's worth it about 3000rpms at this point.. it just won't pull more. Granted I have a tuber on the back.. but that's never been a problem. I've always been able to pull tubes with plenty of acceleration and power. Also replaced fuel/water filter.. no sign of water.. fuel "smelled" normal.

 

[itsathepete]

I agree you are not getting even fuel spray from both injectors. Take apart, inspect, clean, and swap postitions to troubleshoot before throwing parts at it

 

[itsathepete]

You can check the part numbers on the injectors when you take them off. They are likely GM parts than can be purchased much cheaper from an auto parts store than a boat dealer.

 

[alldodge]

Need to scan for codes, can use a resistor LED or a mulitmeter with tone at the DLC connector. Jump the 2 pins at the DLC connector to active scanning, turn key ON (don't start) then watch light or meter for flashes/tones.

Example; 14 will show up as flash, short pause, flash, flash, flash, flash longer pause. The code will repeat 3 times and then go to the next code if there is one

Check timing and see if it is advancing. To check timing need to jump pins A and B to place in base timing mode

 

[Dhassan76]

Alldodge.. thanks for the help! I got codes 12 and 44.
Now with that said, I don't know how old those codes may be.. but regardless it might help. Do you know what those codes may be? I can't find that information on the internet..

 

[Dhassan76]

I can't find code 12.. code 44 is knock sensor? Says ECM is not detecting a knock sensor signal.. would this put the ECM in limp mode and retard timing?

 

[alldodge]

Code 12 is a self test and means the self test is ok
Code 44 is ECM does not see any activity. This can be caused by a bad knock sensor, bad connection between sensor and ECM. The code will not reduce power but does sound alarm. Another is having similar and see post 27 for explaination

https://forums.iboats.com/threads/2002-volvo-penta-gxi-5-0-beeping-issue.756444/page-2#post-5772606

 

[Dhassan76]

So bear with me here on my dumbness.. but on one hand you say if ECM does not see activity it will reduce power. But then you say the code (for no activity) will not reduce power.
Some of this might make sense.. as basically I am down on power. And from some reading I have read it derates power by cutting down one injector? Perhaps that is why I see one injector not spraying as much? I will dig around and see if wiring is broke or such.. but if not I suppose I should just get a new sensor?

 

[alldodge]

My bad, I edited it, keep thinking Merc and then noted it was VP and didn't go back and change it. I changed it now

I would fined a place to clean and flow test the injectors