Continuing Problem with 2021 VP 250 hp 4.3 DI

[harringtondav]

Previous post I thought I'd fixed a bad fuel problem. ...the engine problems are sticking.
Clean fuel, new fuel filter. Continued rough operation idle through WOT, intermittent alarm beeps, 1/2 or less power at hole shot and at plane. Strong gasoline smell in exhaust at no wake. It seems to be guzzling gas. No engine bay gas leaks. No Diacom DTCs other than random misfires which I already know.
The engine is under VP warranty until August. Hoping for a self fix before the 4th of July weekend. I shared the symptoms with the dealer service mgr asking for self help or useful input if I have to haul it in. He focused on fuel transfer pump pressures, saying too high could be a problem. He mentioned a clogged screen in the flow. Quick look at the shop manual doesn't show any screen. The boat has run like a beast until splashing after the last winter layover. Winterized each year with 50:1 premix through the fuel system.
I'll check transfer pump pressures tomorrow and recheck DTCs.
Does anyone know the location of this screen? Any other suggestions?
Thanks, Dave.

 

[muc]

I'm not aware of any screens in this system, other then in the injectors. Your phone contact might have been thinking about older systems with the fuel pressure regulator on the fuel rail.
Yes, 1st step is to check the 2 pressures at the pump.
top port is 60 ± 5 PSI
bottom port is 10–40 PSI

Couple of questions, does this engine have catalysts? When you pumped the old fuel out of the tank, did you suck it out the fuel line or pull the sending unit and suck it dry from the lowest corner of the tank?

Diacom record files might be helpful. If you would like to post them, I would be happy to look at them.

If you would like my advice on how to do a recording, here it is:

Start with a cold engine and the boat in the water.
1. Connect Diacom
2. Turn on batt switch, turn on key switch -- but don't start engine
3. Start Diacom recording -- let run for 30 seconds to one minute
4. Start engine
5. Check that Diacom is still recording, it's not uncommon for it to have lost communication during starting. If it did, save that recording and start another one.
6. Run the boat gently at idle to 1500 RPM until up to operating temp
7. Run the boat up to full speed --- take your time, looking to get data here so advance the throttle slowly (spend one to two minutes) now slow back down to minimum wake and idle in neutral for awhile. Use the trim as you normally would.
8. Do a "ski start" -- full throttle all the way to full speed and trimmed out, now back to idle fairly quickly.
9. Drive boat back to the dock/ramp and shut off
10. Stop recording and name the files

Volvo is "special" when it comes to recordings. There can be a few monitors that need their own separate recordings. Here is what you might see.




Start with Engine Data and try and get O2 Feedback, Misfire, Fuel Control and Injector.

To use Diacom for anything more then a code reader is a learning curve and will take some time depending on how much knowledge about EGC diagnostics you have.

Happy to help if I can.

 

[muc]

Also according to the Volvo website, you have an open recall?

Your product is subject to a recall campaign. Please contact your Volvo Penta service dealer to schedule an appointment. State your serial number as a reference.

Might want to ask your dealer about this.

 

[jimmbo]

How fast is that 4.3 spinning to get 250hp, 6500 rpm?
Still it would be a pretty weak Hole Shot.

 

[harringtondav]

I'm not aware of any screens in this system, other then in the injectors. Your phone contact might have been thinking about older systems with the fuel pressure regulator on the fuel rail.
Yes, 1st step is to check the 2 pressures at the pump.
top port is 60 ± 5 PSI
bottom port is 10–40 PSI

Couple of questions, does this engine have catalysts? When you pumped the old fuel out of the tank, did you suck it out the fuel line or pull the sending unit and suck it dry from the lowest corner of the tank?

Diacom record files might be helpful. If you would like to post them, I would be happy to look at them.

If you would like my advice on how to do a recording, here it is:

Start with a cold engine and the boat in the water.
1. Connect Diacom
2. Turn on batt switch, turn on key switch -- but don't start engine
3. Start Diacom recording -- let run for 30 seconds to one minute
4. Start engine
5. Check that Diacom is still recording, it's not uncommon for it to have lost communication during starting. If it did, save that recording and start another one.
6. Run the boat gently at idle to 1500 RPM until up to operating temp
7. Run the boat up to full speed --- take your time, looking to get data here so advance the throttle slowly (spend one to two minutes) now slow back down to minimum wake and idle in neutral for awhile. Use the trim as you normally would.
8. Do a "ski start" -- full throttle all the way to full speed and trimmed out, now back to idle fairly quickly.
9. Drive boat back to the dock/ramp and shut off
10. Stop recording and name the files

Volvo is "special" when it comes to recordings. There can be a few monitors that need their own separate recordings. Here is what you might see.

View attachment 409162


Start with Engine Data and try and get O2 Feedback, Misfire, Fuel Control and Injector.

To use Diacom for anything more then a code reader is a learning curve and will take some time depending on how much knowledge about EGC diagnostics you have.

Happy to help if I can.

Thanks muc, I was hoping you'd pick up on this one.
Answers to your questions: This is a rare no-CAT engine. I used my electric fluid extractor on bucket to pump the tank. I removed the tank supply hose from the transfer pump and threaded the tube into the thank. I think it bottomed. About 14 gallons which seemed about right. Fuel gage was pegged empty. There could have been a little gas still in the tank. Then I added five gals of fresh gas to get to the gas dock. A little stutter at first but then smooth operation. After another 10 gals at the dock it ran fine for 1/2- 1 hr. Then the alarm and misfiring returned. Previous WOT was about 5.2K. Now about 4.4K. With the factory 21P it would hit the limiter at 5.8K, so I'm running a 22P to hold it at 5.2K with nearly the same top GPS speed of 52 mph. ....maxing at 38 mph now.
I changed the fuel filter when the problem first showed, before I pumped the tank. I changed the filter when the problem returned. No help.
I'll record data today per your instructions. ....dang laptop screen is very hard to read in the sun.
VP sent me notification about a possible fuel test schrader valve under torqued. Nothing else, but I'll recheck for more.

 

[harringtondav]

How fast is that 4.3 spinning to get 250hp, 6500 rpm?
Still it would be a pretty weak Hole Shot.

It is limited to 5.7-5.8 which I got with the OEM 21P prop. I'm running a 22P now @ 5.2K at about and GPS 48 mph. Boat jumped on top of the water w/in three seconds, maybe 10 seconds more to 5.2K. Yesterday I reckon over 30 seconds to max at 4.4K, 38 mph. ....seemed half power at best.

 

[harringtondav]

I'm not aware of any screens in this system, other then in the injectors. Your phone contact might have been thinking about older systems with the fuel pressure regulator on the fuel rail.
Yes, 1st step is to check the 2 pressures at the pump.
top port is 60 ± 5 PSI
bottom port is 10–40 PSI

Couple of questions, does this engine have catalysts? When you pumped the old fuel out of the tank, did you suck it out the fuel line or pull the sending unit and suck it dry from the lowest corner of the tank?

Diacom record files might be helpful. If you would like to post them, I would be happy to look at them.

If you would like my advice on how to do a recording, here it is:

Start with a cold engine and the boat in the water.
1. Connect Diacom
2. Turn on batt switch, turn on key switch -- but don't start engine
3. Start Diacom recording -- let run for 30 seconds to one minute
4. Start engine
5. Check that Diacom is still recording, it's not uncommon for it to have lost communication during starting. If it did, save that recording and start another one.
6. Run the boat gently at idle to 1500 RPM until up to operating temp
7. Run the boat up to full speed --- take your time, looking to get data here so advance the throttle slowly (spend one to two minutes) now slow back down to minimum wake and idle in neutral for awhile. Use the trim as you normally would.
8. Do a "ski start" -- full throttle all the way to full speed and trimmed out, now back to idle fairly quickly.
9. Drive boat back to the dock/ramp and shut off
10. Stop recording and name the files

Volvo is "special" when it comes to recordings. There can be a few monitors that need their own separate recordings. Here is what you might see.

View attachment 409162


Start with Engine Data and try and get O2 Feedback, Misfire, Fuel Control and Injector.

To use Diacom for anything more then a code reader is a learning curve and will take some time depending on how much knowledge about EGC diagnostics you have.

Happy to help if I can.

I have the .rec files ready. I tried attaching them here, but the file type isn't supported. Also tried a pm here. Unable to attach. Requesting your email via pm, and sharing mine.
Thanks,
Dave

 

[muc]

Hey Dave, I don't know how to post them on iBoats. But it can be done.
Here is a recent post.

8.1 Gi-J SPN 29 FMI 4, 697, 698, 699 FMI 5, SPN 713 FMI 4

I have a 8.1 Gi-J non-catalyst with serial # A140969 in a 2011 Cobalt. I have the following fault codes and need help as I don't have access to any EGC manuals. I ordered EGC Diagnostic Manual 7749393 but don’t know when it will be here and no local dealers have it. Codes were pulled using a...

forums.iboats.com

I'm sorry, but I don't do anything outside of the board. Maybe one of the Mods or one of the posters that have posted .rec files can help?
I like these types of forums that can have multiple sets of eyes looking at the problem.

I do have another question, I can't quite follow your description of how you sucked out the fuel. When you say -transfer pump- do you mean the fuel feed pump mounted on the engine? Did you get any fuel pressure readings today?

 

[harringtondav]

Hey Dave, I don't know how to post them on iBoats. But it can be done.
Here is a recent post.

8.1 Gi-J SPN 29 FMI 4, 697, 698, 699 FMI 5, SPN 713 FMI 4

I have a 8.1 Gi-J non-catalyst with serial # A140969 in a 2011 Cobalt. I have the following fault codes and need help as I don't have access to any EGC manuals. I ordered EGC Diagnostic Manual 7749393 but don’t know when it will be here and no local dealers have it. Codes were pulled using a...

forums.iboats.com

I'm sorry, but I don't do anything outside of the board. Maybe one of the Mods or one of the posters that have posted .rec files can help?
I like these types of forums that can have multiple sets of eyes looking at the problem.

I do have another question, I can't quite follow your description of how you sucked out the fuel. When you say -transfer pump- do you mean the fuel feed pump mounted on the engine? Did you get any fuel pressure readings today?

I used my engine oil extraction pump. Three bucket dumps.
I spent a few hrs analyzing the data graphs. I couldn't access the fuel pump Schrader valves easily, so I moved on to recording data. My observations:
Engine off, key on 22 psi. I assume the high pressure sensor is accurate at low pressure. If so the transfer pump pressure looks very low.
Engine running fuel, rail pressure increases from 710 psi no wake idle to over 2k psi at WOT, which is about 600 rpm lower than good performance.
TPS actual increases proportional to engine RPM.
Injector pulse width maxes at 15.3 ms at throttle up, drops, climbs to 4.5 ms at 4200 rpm, then drops to 3.7 ms at 4700 rpm.
Injector pulse width seems to hang under 4 ms through higher throttle demand. This seems to me to be a factor in the low power and random misfires.
Misfire data shows only one or two cylinders. ...haven't graphed all six yet.
I haven't dug into the O2 data much because I don't know what to look for. But with the strong gasoline odor in the exhaust I'm wondering if the ECM is dialing back the fuel delivery to compensate for rich exhaust. If a fuel, leak it seems engine internal. Engine bay smells OK. I'll give the engine oil dipstick a check for making oil, and gas smell.
Your thoughts and next checks are appreciated.
Thanks.

 

[harringtondav]

Hey Dave, I don't know how to post them on iBoats. But it can be done.
Here is a recent post.

8.1 Gi-J SPN 29 FMI 4, 697, 698, 699 FMI 5, SPN 713 FMI 4

I have a 8.1 Gi-J non-catalyst with serial # A140969 in a 2011 Cobalt. I have the following fault codes and need help as I don't have access to any EGC manuals. I ordered EGC Diagnostic Manual 7749393 but don’t know when it will be here and no local dealers have it. Codes were pulled using a...

forums.iboats.com

I'm sorry, but I don't do anything outside of the board. Maybe one of the Mods or one of the posters that have posted .rec files can help?
I like these types of forums that can have multiple sets of eyes looking at the problem.

I do have another question, I can't quite follow your description of how you sucked out the fuel. When you say -transfer pump- do you mean the fuel feed pump mounted on the engine? Did you get any fuel pressure readings today?

Hey Dave, I don't know how to post them on iBoats. But it can be done.
Here is a recent post.

8.1 Gi-J SPN 29 FMI 4, 697, 698, 699 FMI 5, SPN 713 FMI 4

I have a 8.1 Gi-J non-catalyst with serial # A140969 in a 2011 Cobalt. I have the following fault codes and need help as I don't have access to any EGC manuals. I ordered EGC Diagnostic Manual 7749393 but don’t know when it will be here and no local dealers have it. Codes were pulled using a...

forums.iboats.com

I'm sorry, but I don't do anything outside of the board. Maybe one of the Mods or one of the posters that have posted .rec files can help?
I like these types of forums that can have multiple sets of eyes looking at the problem.

I do have another question, I can't quite follow your description of how you sucked out the fuel. When you say -transfer pump- do you mean the fuel feed pump mounted on the engine? Did you get any fuel pressure readings today?

I just saw your Zip file reference. I'll try this...tomorrow. Thanks.

 

[harringtondav]

Hey Dave, I don't know how to post them on iBoats. But it can be done.
Here is a recent post.

8.1 Gi-J SPN 29 FMI 4, 697, 698, 699 FMI 5, SPN 713 FMI 4

I have a 8.1 Gi-J non-catalyst with serial # A140969 in a 2011 Cobalt. I have the following fault codes and need help as I don't have access to any EGC manuals. I ordered EGC Diagnostic Manual 7749393 but don’t know when it will be here and no local dealers have it. Codes were pulled using a...

forums.iboats.com

I'm sorry, but I don't do anything outside of the board. Maybe one of the Mods or one of the posters that have posted .rec files can help?
I like these types of forums that can have multiple sets of eyes looking at the problem.

I do have another question, I can't quite follow your description of how you sucked out the fuel. When you say -transfer pump- do you mean the fuel feed pump mounted on the engine? Did you get any fuel pressure readings today?

Here are the compressed .rec files. When you click to open this should show up in your downloads folder where you can open it to see the four individual .rec files.
Please let me know if you have trouble opening, and if you need more data.

 

[harringtondav]

@muc More info. I checked the transfer pump pressures. High pressure =50 psi. Low pressure/internal pump pressure = 8 psi.
Not good. Hopefully it explains the problem. I've noticed erratic O2 trims, closed loop switching to active and back erratically. An generally low injector pulse widths.
Thanks.

 

[muc]

Hi Dave, What did you connect the oil extractor to?
Were these pressures checked with the engine running under moderate load?
Assuming this was a valid pressure test and you have confidence in your fuel pressure tester, yes that's a little low. Because it's just a little low I would be checking for air suction leaks and/or a restriction in the boat side before thinking about fuel cell replacement.

I started to look at the .rec files you posted, but don't see a running engine data file. But at this point the fuel pressure issue must be corrected before anything else can be diagnosed.

 

[harringtondav]

I removed the fuel inlet at the transfer pump and threaded the extractor tube down into the fuel tank. Maybe a splash of fuel remained.
After refueling and getting the .rec files, I connected the gauge to each schrader valve and tune the engine to 'on'. The transfer pump cycles for about 8-10 seconds, reaches pressure and stops. I was up, dry on the lift. I started the engine briefly to get a reading. 8 psi on the low side vs 10-40 psi spec. 50 psi on the high side vs. 55-65 psi spec. Idle load only.
I'll get Diacom engine data running, and also each pressure. If the pressures are still low I'll see if the dealer will warranty a new transfer pump. ....else I have to wait several weeks before he can get to it.

 

[harringtondav]

Hi Dave, What did you connect the oil extractor to?
Were these pressures checked with the engine running under moderate load?
Assuming this was a valid pressure test and you have confidence in your fuel pressure tester, yes that's a little low. Because it's just a little low I would be checking for air suction leaks and/or a restriction in the boat side before thinking about fuel cell replacement.

I started to look at the .rec files you posted, but don't see a running engine data file. But at this point the fuel pressure issue must be corrected before anything else can be diagnosed.

@muc
I rechecked fuel pressures today from idle to WOT.
Low pressure 10-11 vs spec 10-40. High pressure 65-70 vs spec 55-65. Little to no variation as load increased......hopefully close enough for you to take another look at the .rec files
I re-ran all .rec files attached. Recorded from idle through a moderate/hard acceleration to WOT.
Thanks for your time and help.

 

[muc]

ok, I'm not 100% sure on this. But I have had more then a few customers that would tell me "Maybe a splash of fuel remained" or I drained the tank completely dry". But from their description of the symptom, it sure sounds like a bad fuel issue. So I question them about how did you drain the tank? And more often then not they describe some version of removing the fuel line from the pump and sucking it out. But the trouble with doing it like that ---- it doesn't work!
See, the problem is that a 17' to 23' I/O runabout will have a below the floor keel tank. So on all the boats I've worked on, there will be an anti siphon valve screwed into the fuel withdrawal tube and that tube will have 90° fitting at the top. So it's improbable that the tube you pushed down the fuel line toward the tank was able to make it past the stainless steel check ball and spring and then make it around the 90° fitting. Now in your case I might be wrong as I haven't worked on a small new runabout in over a decade. I suggest you follow the fuel line all the way to the tank to check. On small boats you can sometimes see in the engine compartment, but usually you will need to remove an round access plug in the floor or under the seats.

I see that you posted while I'm making this post. I'll finish this post and then hopefully later tonight I'll have time to look at the files.

Ok back to why this might be important to you. The fuel withdrawal tube in your gas tank will stop well short of the bottom of the tank, anywhere from 1" to 5". So when you "run out" of gas while driving the boat, there will be anywhere between 3 to 5 gallons still in the bottom of the tank. In a gas tank the bad fuel and crud will always be at the bottom. It will stay there until the boat starts moving around and then get sucked up.
What concerns me is, first it sounds to me you are dealing with a "bad" dealer. I base this off of your comment that they are "several weeks before they can look at it" If this is the dealer you bought the from -- that's unacceptable. A good dealer will find a way to get you taken care of. If it's a dealer you didn't buy the boat from -- that's normal this time of year and I have worked for dealers that wouldn't do ANY warranty work on boats that weren't purchased from us. If you do have bad fuel, this is something that's not covered under warranty. So if that's the case it might be best for you to correct it. If you decide to do this, post some pics of the tank and I'll walk you through how to get all the bad gas out.
I'm not there and diagnosis over the internet isn't easy. The picture you posted of the fuel is from the wrong angle. Only you can determine if you have bad fuel. But your symptoms fit. Now that I see the new fuel pressures you just posted --- I'm 50/50.

I'm out of time, will try to complete my thoughts later.