Engine Won't Start: Troubleshooting & Fixes

Hello everyone,

I'm new here because my car isn't working anymore. I drive a Fiat Doblo, manufactured in 2008, with a 1.3 Multijet engine, 84 horsepower, and a mileage of 115,000 km.
"The car was driving along when it suddenly cut out with a 'plopping' sound (according to my wife, I wasn't there), and wouldn't restart. The engine is still turning over, but I think it feels heavy, although that's just a feeling and rather subjective."
Following that, I read the error codes, and they indicated a faulty mass airflow sensor (MAF), a camshaft position sensor, and a fuel pressure sensor with low pressure.
Okay, I've checked to see if diesel fuel is reaching the high-pressure pump and also that diesel fuel is returning from it. Both of those seem to be working correctly. However, no diesel fuel is getting from the high-pressure pump to the rail! I then checked the pressure control valve, which seems to be functioning properly. Next, I removed the high-pressure pump, and it appears to be okay as well (it can be easily turned by hand). The only thing that seemed odd was that the feed pump doesn't always run when the ignition is on, and if it does, it only runs for a short time. However, it has two control lines from the engine control unit, and I don't know how the logic works – i.e., when the pump should be running and when it shouldn't. There's also no visible corrosion on any of the connectors. Everything looks good. Now I'm at a loss. I can rule out the mass airflow sensor (MAF) and the pressure sensor as the cause, because otherwise the engine would have gone into limp mode and shut down. The only thing I'm unsure about is the camshaft sensor. Could the control unit reduce the output from the high-pressure pump to the rail to zero? And if so, how?I'm looking forward to hearing your ideas.

Sure, here is the translation of the text from German to English:

"VG" translates to "Very Good" in English.
Tangor.

Hello, please observe the rules.

Have you ever considered checking to see if the timing belt is still in its correct position?

no timing belt, chain-driven camshaft.

Which rule did I violate?

VG

tangor71 wrote:

no timing belt, timing chain. Which rule did I violate? VG

It's possible that you might have "missed" this information during the registration process.

Quote:

We cordially invite you to participate. The requirement for posting in diagnosis-related topics (everything for which a vehicle diagnostic system is needed) is... a diagnostic device from the Dieselschrauber Shop or our software KDataScope, KPower, or the Dieselschrauber license or a vehicle diagnostic support key.

Regards, Mpire.

Okay, I understand. Please provide the text you would like me to translate from German to English.