Volvo D3-110i-C Issues....

[likinsca]

Hello everyone.

I have been having problems with my Volvo D3-110 and hoping that someone here with Volvo experience might have some ideas. I will explain below.


The symptoms:
With the engine in gear, once reaching about 1400 to 1500RPM a "service fuel system" alarm is generated. Simultaneously the engine automatically reduces and limits the RPM to about 1250. Occasionally the engine will shut down immediately after the alarm is sound. The engine has zero difficulty restarting every single time. It's also worth nothing that I have not been able to trigger the alarm while in neutral and it will rev to 2500rpm no problem without any load.

We have already done the basic things of checking the primary and changing the secondary fuel filter. All the filters appear clean. We have changed the fuel pressure sensor and the fuel pressure limiting valve on the common rail. Most recently we changed the MPROP on the high pressure pump. None of these have been able to correct the issue.

Recently we had the Volvo tech come out. The fault codes generated on VOIDA were MID128 PSID50, MID128 PSID71, and MID128 PSID71. This is pointing at the MPROP. The Volvo tech also noted that the engine was hunting rpm a bit at idle suggesting the possibility of faulty injector(s)

The MPROP is new so it doesn't make sense that its generating fault codes but it is. Could this be a wiring issue between the MPROP and the ECU? Perhaps a corroded connection is limiting current flow to the MPROP and causing the pump to send too much pressure to the rail?

Thoughts?

Thanks in advance!

[skipperpete]

Hi likinsca
If the data that the VP tech downloaded indicates that the MPROP is faulting it would definitely be worthwhile reviewing the unit and certainly worth checking the connections..... in fact , every plug connection on the main harness and CPU. The Mprop has two live terminals and is controlled by a negative (ground) so any interference with that would really upset the fuel valve operation.
If you have a twin installation try swapping the sensors between engines and see if any changes occur.
Finally, I would take a careful look at the fuel supply. common rail engines respond differently to suction leaks and a stream of almost invisible bubbles that would be purged from a conventional fuel system via the leakoff return to tank will affect the mprop valve operation. If you want to get a better idea of how this all works then take a browse through the automotive club sites online, the Dodge Ram uses the same Bosch system on its 6 cylinder Cummins and those truck guys really get into the fine detail of trouble shooting..... unlike VP who tend not to share.
I'm sure there must be diesel techs out there in the forum that can help with this, especially since the automotive world is now dominated by common rail.... just not so much in the cruising world.....