Really having trouble with my a4 b7 tfsi, I am still getting a misfire only on idle, have changed coilpacks spark plugs, pcv valve and also done a compression test. I am running out of ideas of what it can be only fault code that comes up on scanner was misfire cylinder 3 and I believe it also said fuel lean at low revs, only other thing I could think of is a injector, but want to make sure before I take whole inlet off. Any ideas?
A4 tfsi idle misfire
- Thread starter Ollie454
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Carbon fouling the inlet valves, common problem on tfsi engines it happens because the fuel is directly injected into the cylinder.
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The carbon build up can restrict air flow into the cylinder disrupting fuelling adaptation or even prevent the valve from closing fully.
https://goo.gl/images/x4pLDF
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Not properly no, any fuel additives will never see the inlet manifold or valves. Walnut blasting seems to be popular.
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If inlet has to come off anyway may as well send injectors off to be tested and cleaned at the same time
I recently had the same problem with my S3 tfsi engine and did all you have done but then i bit the bullet and got the walnut clean done and car runs perfectly . Do you get the needle moving slightly when just sitting like as if it was breathing if so then do a vacumm test as you have a slight leak somewhere normally at the pcv maybe a Oring perished on one off the pipes heading into pcv
