Avensis Cold Start Issue

I had similar symptoms with my Avensis. Is it struggling only when it's cold, or all the time? I'd suggest checking your fuel injection system. Maybe an injector test is a good first step?

It's definitely worse when cold. Once it warms up, it's mostly okay, although fuel consumption has taken a hit. When you say fuel injection system, did you have one specific injector replaced, or the whole set? Was it pricey?

In my case, the problem was with the cold start injector specifically. I'd recommend getting it checked out at a workshop to be sure. They should be able to confirm if it's defective.

For those following, I took it to a workshop, and you were spot on – the cold start injector was indeed defective. Replacing it fixed the rough idle and hard starting! Cost me 515€ all in. Thanks for the advice!