Technical air filter

[smelluel55sx]

i have a mk1 punto 55 sx. I bought a raid hp performance air filter for it which initially seemed to do the job. But recently, if its idling and i put my foot down it will sometimes sound lumpy and will not pick up like it sould. Occasionally it will make a cracking sound which sounds like its coming through the inlet manifold/throttle body. Sounds like the sypmtomes of a weak mixture but shouldnt the engine managment compensate for this?

 

[rpaterson]

I don't know about the 55sx engine, bit I stuck an induction kit on my wife's Sporting. The inlet ducting usually has a pipe that is used to recycle the oil fumes that build up within an engine. It's usually a small pipe that comes from the top of the engine (camcover) and perhaps joins to the old air filter box and also behind the throttle butterfly. I had to blank off a pipe so that the engine wouldn't be sucking in more air than it thought it was. Check that you've got no open ends of pipe anywhere around the throttle body.