C70 cold start rough running

Sounds familiar! I have a Volvo C70 too, though a bit newer. I had similar hard starting and poor running when cold. Fuel injection problems, especially with the cold start injector, can cause that. Have you tried any fuel system cleaners?

Thanks for the quick reply! No, I haven't tried any fuel system cleaners yet. What exactly is the cold start injector, and how would I check if that's the culprit before throwing parts at it? Is it something I can test myself, or am I better off taking it to a workshop?

The cold start injector gives extra fuel when the engine's cold to help it start and run smoothly until it warms up. Honestly, testing fuel injectors usually needs special tools. Given the symptoms, it really sounds like a faulty injector. I ended up just taking mine to a workshop - saved me a lot of hassle in the long run.

Okay, I think I'll take your advice and bring it into a shop. I was hoping it would be something simple, but it sounds like the injection valve could be the problem as you suspected. They've quoted me 515€ for the repair. Thanks for the help diagnosing it!