C30 Diesel Injection Problem

Sounds familiar. First thing I'd check is all the wiring and plugs going to the injectors, especially the ones near the back of the engine. They can get cooked from the heat and start to crumble. Give 'em a wiggle and see if the engine changes tone. Any fault codes?

When you say 'changes tone,' what should I listen for? I got generic OBD-II codes about fuel trim, but nothing specific to the injection system. Should I get a Volvo-specific tool, or can I isolate it with what I have?

If wiggling the wires causes the engine to stumble or momentarily improve, that's a good sign. Generic OBD-II codes can be vague. A Volvo-specific scanner would give you more insight, but the stalling and smoke suggest it's more than just a bad reading. A shop visit might be wise before spending too much.

I had a technician check it. You were right; it was a bad electrical connection in the injection system. Replacing the wiring harness cost 95€. Thanks for the help.