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.