Found a problem where one of the pipes was disconnected under the inlet manifold. Here's a picture showing the pipe disconnected.
The pipe pushes into a bigger pipe to the left of the picture. So I've push them together.
I'm not sure whether the pipe will hold. Maybe need to see if I can get a cable tie in there (not much room).
I'll test the car out of the next couple of days and report back. Hopefully I haven't caused too much damage to the engine!