We were called to diagnose a DAF CF65 that had a symptom where it would simply shut off whilst driving, cutting off completely after 2500 RPM was reached, this fault was not always active, sometimes the truck would drive just fine, but at times the fault was more prominent.
We started off by first looking at fault codes, since this DAF uses a Cummins ISBe engine, Cummin's oem tool - Insite was used to check for fault codes, surprisingly, this truck had quite a few inactive fault codes mostly related to fuel pressure and leaks.
Whenever we have such faults, rail pressure is checked using a manometer, which we did and all checked out at idle, but since this fault was intermittent, we looked at other variables such as the high-pressure pump, fuel filter and such - and found out that the filter itself was clogged.
This fault was rectified buy replacing the clogged filter and clearing all inactive faults.