1.8l fueling problems - backfires.

[Rmachines]

Hey,  i seem to get alot of backfiring when decelerating down a hill for example,  i know its normal for a bit but i get a lot,  but whats worse is when i start the engine it splutters a bit and i have to give it a bit of throttle to get it running properly,  now recently when i do this i get a big BANG and a splutter,  obviously this is overfueling a bit,  its just passed its emissions (Just about)  so it cant be to bad.   

all i get on VAG-COM is air temp sensor but i cant see that causing this as it runs ok.

any ideas what it could be?

cheers.

[boneybradley]

my old driver did similar and a new temp sensor sorted that (oh and check the breather pipes as I had several failures on mine making the emmisions higher and the idle lumpy)

[Rmachines]

I changed the temp sensor when i got the car,  the breathers were cleaned also. its the Air temp sensor i think could be a problem but idle is fine and Air temp sensor causes bad running usualy.

[Rmachines]

any one else any ideas? 

[davero]

I would check all your vacumn hoses again. Really does sound like the symtoms of a split hose

[boneybradley]

on the rear of the engine (going by memory its just under and to the left of the s.p.i unit?) there is a breather that has a 1 way valve (with 2 green bungs in)... check this as if the valve dosent work right or the bungs let air out...this can cause similar issues.

[Rmachines]

ooo i will check that out!  Thats a possibility.