Lexus LX cold start injector issue

Rough running and hard starts sound like a fuel delivery issue, for sure. When you say "cold start injector", do you mean the actual cold start injector, or just one of the regular fuel injectors acting up? Have you tried any fuel injector cleaner in the fuel rail? It might just be a blockage...

Yeah, I was thinking it's the cold start injector, as in, the one specifically for cold starts. But I'm not sure how to test it. And about injector cleaner, can that actually help, or is it just snake oil? What do you reckon?

Okay, if it's the actual cold start injector, those can be tricky. If it's faulty, it might not be spraying enough fuel, causing the poor starting and rough running. Or, it could be leaking, flooding the engine. Cleaner can sometimes help, but honestly, with those symptoms, and that mileage (175892 km!), it might be best to get it checked by a shop. Could be a bad injector valve.

I suspected as much. Took it to a workshop, and they confirmed the cold start injector was kaput. Cost me 515€ to replace, but she's running sweet as now!