Volvo Penta V6-240 Fuel High Pressure Dropping to Zero

[Biz603]

I'm at a lost for what it could be and have been reading intently hoping to find the issue. Hoped @muc or others can advise, but looks like the well is running dry

Thanks for the deep look and trying. I appreciated it.

 

[Biz603]

The only thing I come up with is a different hpfp... 12733993 for the 4.3. Looks like it overlaps the pn for the one you are using. Do I think thats the issue based on the data? No... but I'm at a loss for what else it could be.

Thanks for your input. Open to trying it.

 

[Pmt133]

One other question. When installing the fuel pump, how's the lobe look?

And I don't know if I missed it but what year 4.3 is this?

It's odd to be having the same issue but something is being missed.

 

[Biz603]

One other question. When installing the fuel pump, how's the lobe look?

And I don't know if I missed it but what year 4.3 is this?

It's odd to be having the same issue but something is being missed.

2017.
Not sure what the lobe is. But, after removing the HPFP each time I looked down the hole at the cam it rides on. Admittedly without a flashlight, but under sun light I didn’t notice any excessive wear or scarring. The push pin on the HPFP looked good. Can send pix of that if needed.

 

[Pmt133]

2017.
Not sure what the lobe is. But, after removing the HPFP each time I looked down the hole at the cam it rides on. Admittedly without a flashlight, but under sun light I didn’t notice any excessive wear or scarring. The push pin on the HPFP looked good. Can send pix of that if needed.

The lobe, eccentric, cam lobe etc. Just checking. I've seen worn lobes from fuel pump failures cause issues too but usually it's noticeable either in the fuel or visually scarred or worn down. I don't think it was the problem either but worth asking just to rule out anything else.

 

[Lpgc]

Sorry I didn't visit this forum for a while but I checked this thread as soon as I visited... Just don't have anything to suggest.

Any new developments?

 

[Biz603]

Sorry I didn't visit this forum for a while but I checked this thread as soon as I visited... Just don't have anything to suggest.

Any new developments?

The latest . . .
I uploaded a zip file with several test runs in the lake, under load (a few posts back). Some test runs failed as expected, some others work just fine, like nothing was wrong, and achieved 5800 rpm, max for this engine. It was 50/50.
Here’s the really strange thing, brought the boat back home, fired it up one last time before winterizing it, and it worked just fine!! Like nothing was wrong. I couldn’t get it to fail again with several tries. Crazy I know. I couldn’t believe it. 20 minutes of a matrix of throttle ramps and position, ZERO failures!?!
I have no idea why.
I winterized it and it’s put away now.
When I take it out again in May I’ll post back here again.
Until then a big THANK YOU to all who contributed!! Much appreciate!!
Until May . . .