This is how your engine bay should roughly look like.
This is the air filter housing cover removed. Note the 3 screws and 4 clips.
The engine bay with the air filter cover removed.
What you get when you lift up the entire air filter housing.
Note the green plug and red hose. Igmore the yellow one.
Unplug the green plug, and leave the red hose in. Follow
the red hose to the end at the throttle body. You want to check
the short hose which is to the left of it on the throttle body.
When you unplug the green plug, you can then sit the hosuing over here.
Should have something like this in front of you.
See this little black container ? The hose on the right goes to the
throttle body, the one on the left goes to the map sensor. The hose
that goes to the throttle body is about 10cm long at the most, both its
ends are a rubber "L". There L joins can split right up to where its a right
angle. I don't think they like the heat back behind there and overtime just
get weak.
The ends of the hoses that attach to the throttle body are down behind here....
Same view, but a bit further back to give you some reference points.
THIS is the hose you want to check out. This is THE hose I had on my rover, you can see the split on the left hand end.
(I now know "Sensor of some sort" is the MAP sensor....which is kinda important to the whole engine running properly, lol)
Check the short black hose really well. The smallest crack/split will
make the car run like crap and go through a heap of fuel.
Hope this helps someone!!! I'd have loved to have this when my Rover
decided to annoy me!