More FSI Misfires

Thanks for updates! Great to hear Philip's issue seems to be solved. :)

I hadn't read/noticed any recommendations about not using fuel additives. Sooo, at the moment I'm starting my second tankful boosted with Injection Cleaner by Liqui Moly. :eek: I wasn't and am not especially optimistic about it, but it was too cheap not to try (compared to real injector removing and testing work). Today I did some motorway driving with heavy accelerations, hoping to get more fuel through injectors. It did not feel like improving. Actually, engine was running even worse than usual in some point on my way back home. Loss of power and clear misfires on low revs when leaving traffic lights. Will be interesting to see how it works in morning with cold engine.

I'm starting to suspect my injectors even more...

I am not aware of these terraclean or hydrogen cleaning. Based on my experience with this near 180000km driven BAD I wouldn't be horribly worried about internal deposits of the engine. It was opened in January and workshop guys told it wasn't bad at all. A couple years earlier when the throttle body was cleaned situation was similar: it wasn't too bad. Also, cleaning it didn't affect engine idle/running. Everything is possible of course. Perhaps engine situation could be examined with endoscope (spark plug holes, or from intake side..)?
 
yes when i had my injectors fail -it was spotted by putting a camera down the plug hole. The mechanic noticed wet injector tip and wet piston. Up to that point we had done almost every part --fuel tank pump-high pressure pump-egr-lambda-nox-throttle body-air mass ---then bingo new injectors all old bits put back on and its been good for over 100k miles. cheers mike
 
just to add to this thread. my FSI with 104k on it has been hestitant between 2000 and 3000 revs for a while now, like a year.... i know i have a minor air leak on the intake system somewhere, but can't find it for now. i thought that was causing hestitation. having read a couple of threads on here about injector cleaning i put a can of liqui moly petrol injector cleaner into about 1/3 tank petrol and took it for a 20 mile drive. i would say within 2 miles i could feel the difference. it now pulls much smoother, revs more freely and seems to have more power. happy days, £5.70 for 300ml delivered off ebay, now where is that air leak......
 
That's a great result nod you confirming this along with someone else recently is really starting to confirm that injector cleaner is the way to go before any other expenditure and costs all of pennies and zero time to perform.
 
Philip said:
Trying to track down the cause of misfire codes on an FSI - problem arose on starting, the car had been parked for a couple of hours after a brisk 40 mile motorway journey. Engine light was flashing at idle and the following codes weres stored:

16684 - Random/Multiple Cylinder Misfire Detected;
16685 - Cylinder 1: Misfire Detected; and
16687 - Cylinder 3: Misfire Detected.

The flashing check engine light goes out when driving and returns when sitting at idle - there is a very slight but noticeable roughness to the idle, just evident in the rev counter needle. Occasionally it will illuminate constantly, but only briefly.

Plugs are about 5k miles old and are all in good condition and the same good colour; I've swapped all plugs and coilpacks, but the fault codes stay with cylinders 1 and 3.

The only problem I've found is a tiny pinhole in the corrugated EGR pipe, which looks like it has been caused by the wiring bracket attached to the side of the head rubbing on it - I covered this with a blob of superglue as a temporary test, but it hasn't made any difference.

I've also cleaned the main earth on the chassis rail and the one on the cylinder head (both were already clean and didn't really need doing) and gone through all the visible ignition connectors with contact cleaner. I also reset the throttle body with VCDS, just to see if it made any difference (it didn't); inlet and throttle body both look very clean. It's had two or three cans of Normfest fuel system cleaner through it over the past year and the fuel filter is also about 5k miles old. It has always been run on Super Unleaded in my ownership (V-Power whererever possible) and has done about 104k.

Any other suggestions before a compression test and pulling the injectors?
Click to expand...

Hi I had the same problem with my 1.6 FSI same codes too when on idle mine was ok but when I drove there was a loss of power and it started to misfire what solved the issue was a high pressure fuel pump

Hope this helps
 
I've got the same fault as the OP with my FSI. Car starts but idles roughly for about 20 seconds. In that 20 seconds the warning light flashes. After 20 seconds the idle smooths out and the warning light stays off. Torque shows:

Pending Fault Log
------------------
P0300: Random/Multiple Cylinder Misfire Detected
P0301: Cylinder 1 Misfire Detected
P0302: Cylinder 2 Misfire Detected

It's only happened twice so far. Yesterday is was on the first drive of the day on a cold engine. Today it was on an engine that had only been off a couple of hours. Between the two instances it's started up with no issues three or four times. I haven't noticed any loss of power. The car was MOTed and serviced in November.
 
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