My XR4x4 2.9 has been running a little rough from cold recently. This problem is slowly gettign worse and it started popping and banging when cold. Then when idleing the revs started to fluctuate between 400 and 1600 and now it wont even run. As soon as i start it it stalls.

Have checked

spark plugs
cleaned leads but not replaced
cleaned icsv
got a fault code reading of 36 which is air flow meter votage but checked these and voltage is spot on and have physically watched the meters opening and closing.

Any ideas would be most welcome.

cheers