HPDI High Pressure fuel pump failure?

[ncampion]

I have twin 200hp HPDI motors and the port motor will not rev beyond about 2400 rpm and is rough running. Replaced all filters including the small basket filters in the injectors and pump. Mechanic with YDS checked out and first replaced the TPI which made no difference then says the high pressure pump is not putting out correct pressure at higher rpms. This is an expensive part new so I sourced a used one claimed to be taken off a good running motor. Mechanic installs this pump and says that it is no good also. Losing confidence in this mechanic. What are the odds of two pumps being bad? Is it possible to rebuild these pumps like diesel injector pumps? I should mention that I'm in a small town in Baja and this mechanic is pretty much the only **** in town. Any help???

I suppose I should mention a few of the things I have done to try to diagnose. I think I have ruled out bad fuel as the tank has fresh fuel and the Stb motor runs perfectly. I also tired swapping the ECUs and Injector Drivers from the good engine to the bad and made no difference. The plugs on the bad engine are very black and sooty looking, not wet at all.

[boscoe99]

Was the high pressure pump found to be not outputting rated pressure via YDIS?

Unusual for one pump to fail let alone two in a row.

Flagship Marine can rebuild the pump. See page 19. http://www.flagshipengine.com/2010%20Catalog.pdf

If I had two motors of the same model I would swap the HP fuel pumps just to verify that it is kaput.

[boscoe99]

Was the high pressure pump found to be not outputting rated pressure via YDIS?

Unusual for one pump to fail let alone two in a row.

Flagship Marine can rebuild the pump. See page 19 of their online catalog.

If I had two motors of the same model I would swap the HP fuel pumps just to verify that it is kaput.

[zenoahphobic]

I wouldn't jump onto your mechanic yet.
Two new pumps failing in a row has a very low odds of happening, but you sourced a used one from supposedly a good engine running, who knows when last. So the probability doesn't calculate this way.
You would question that second hand pump first. Even if the seller is honest, he may have just assumed it was, because something must not have been good with that motor either for it to be parted out for sale!
Having two engines allows you to fault find by substitution.
The advantage of doing this is minimal cost. However throwing parts at a faulty engine is not really good diagnosis practice. You really have to be sure that the component is faulty this way, and not that it is just more able to cope with another fault condition elsewhere.
So by substituting parts from a similar aged and run motor has the possibility of coming to the wrong conclusion. The truth table (Rodbolt style), fails; the substitute part is used and will eventually also fail (everything wears out), who's to say when, could be after it was swapped into that faulty engine.
This is why one always need to keep in mind, that even new parts need to be verified as working as they should.
As suggested comparing pressure outputs to specification for both pumps needs to occur before you can dismiss the original pump (and the secondhand one).

[99yam40]

knowing what the high pressure PSI is would help.
just taking the word of someone that it is not what it is suppose to be would be hard for me to take as the problem.
is it too high or low?

not many have the equipment to measure the pressure, but as Boscoe mentioned the YDIS is a good tool for these motors.

Did Rodbolt say in the past that a Volt meter could be used to read the output to the ECU , and be converted to PSI?

[boscoe99]

99yam have you seen the "unapproved" message before? First time for me. In blue no less.

If the mechanic used YDIS to measure the TPS voltage he could have seen the fuel pump output pressure. No mention of the mechanic taking parts from the good motor to try on the bad motor. Just a trend of throwing parts at the problem.

[walleye1]

I have never seen a pump go bad, i have seen the harness going to the psi sensor get chafed and short out.

[99yam40]

99yam have you seen the "unapproved" message before? First time for me. In blue no less.

If the mechanic used YDIS to measure the TPS voltage he could have seen the fuel pump output pressure. No mention of the mechanic taking parts from the good motor to try on the bad motor. Just a trend of throwing parts at the problem.

where did you see that warning?
I have not noticed one before, but not sure where I should be looking for it

[DennisG01]

99yam have you seen the "unapproved" message before? First time for me. In blue no less.

I've gotten an unapproved message if I edited it more than once in a short period of time. Sometimes I type too fast and don't proofread before clicking reply.

[boscoe99]

where did you see that warning?
I have not noticed one before, but not sure where I should be looking for it

It was up for a while. Blue background. It is gone now.

I will repost and see if it happens again.

[boscoe99]

Was the high pressure pump found to be not outputting rated pressure via YDIS?

Unusual for one pump to fail let alone two in a row.

Flagship Marine can rebuild the pump. See page 19 of their online catalog. http://www.flagshipengine.com/2010%20Catalog.pdf

If I had two motors of the same model I would swap the HP fuel pumps just to verify that it is kaput.

[boscoe99]

Better look quickly. Seems to be the link to a place to get the pump rebuilt is the problem.