2k6blacka8

There is a function on how you check your fuel trims on VCDS. Search the VCDS website and it should tell you how to access freeze frame live data. I did a while back but I totally forgot how to access them. Or you can search the forums on here on how to do it. That will give you an idea if it's running lean or rich. Concentrate more on the short term fuel trims though.

a_alyte

I'm not sure what to make of my freeze frame data but according to the Rosstech site a neg value indicates the engine is running rich, and vise versa. I'm on my third 12 oz bottle of injector cleaner which may not be enough to make a difference but I have a feeling this approach may not cut it. I'm thinking of trying a direct fuel injection cleaning before swapping injectors.

I meant to label the old plugs to know which one came from what cylinder but it slipped my mind during the process. Two of the cylinders had a small drop of oil visible in the hole, I attached a pic of the old plugs since I have them.

Freeze Frame Data for address 7E8
PID02 DTC that caused freeze frame data storage: P0307
PID03 Fuel system 1/2 status: Closed loop, using O2 sensors
... Closed loop, using O2 sensors
PID04 Calculated load value: 92.9 %
PID05 Engine coolant temperature: 95 °C
PID06 Short Term Trim - Bank 1: -2.3 %
PID07 Long Term Trim - Bank 1: -0.8 %
PID08 Short Term Trim - Bank 2: 9.4 %
PID09 Long Term Trim - Bank 2: 3.1 %
PID12 Engine RPM: 5810 /min
PID13 Vehicle speed: 92 km/h
PID14 Ignition timing advance for cyl #1: 22.5 Degrees
PID15 Intake air temperature: 16 °C
PID16 Mass Air Flow: 231.19 g/s
PID17 Throttle position sensor: 86.3 %
PID18 Secondary Air Status: Atmosphere/off
PID31 Time since engine start: 887 s

a_alyte

I haven't made any progress with this misfire I'm dealing with but something surprised me today. I was using an OBD2 scanner on a different vehicle when something told me to see if it would connect to the A8. Sure enough it did and immediately showed a pending code for 'misfire cylinder 7.' I know vcds is much more in depth but for some reason I was under the impression OBD2 was incompatible. I haven't tried erasing codes or anything so I can't speak on that.

I just ordered a new coil just to see if it changes anything and I'm also awaiting two cans of bg 44k, maybe it can do more than techron in my case. I'm just trying to exhaust every option before removing the manifold to replace the injector. I'm thinking of replacing the fuel filter first since I'm at 95k and doubt its ever been changed, about to do my first oil change also.

dvs_dave

All cars have to be compatible with OBD2. That's the minimum level permitted by the EPA. VCDS goes beyond what OBD2 can do and allows control of manufacturer specific equipment that doesn't come under OBD2 standards.

dvs_dave

FSI fuel system (Direct Injection) is a whole different animal, especially when comparing the operating pressures. DI fuel systems run incredible pressures up to 2900 psi (200 BAR), vs up to around 50 psi for port injection. As a result separating the fuel rail from the injectors means you also have to replace the special single use injector/rail seals which are around $50-75 a pop. With 8 of them needed it adds up quick!

a_alyte

I'm anxious to install a new injector but my house is down to one car. I'm not sure how long it will take me but I'd be rushing since my wife needs my car also, until we find her one. I think I'm just going to buy the injector and if I decide to go to an Indy shop just pay for labor. The question I have is should I go ahead and buy a new intake manifold gasket for the one side (cylinder 7) also?

I sure wish the manifold didn't have to be removed lol.

mishar

On FSI engines manifold has to be removed in order to access injectors. It is one piece so you need gasket for both sides. It may be good idea to let professionals do that.

parkrog

Are you using any coolant? I started to have same problem on start up. One cylinder was misfiring on start up and slow use of coolant. Had small head gasket leak. Managed to seal head gasket with additive flush procedure. Sounds like injector NOT coil pack.

a_alyte

Which additive did you use for the head gasket leak? I do lose a small amount of coolant but I was thinking expansion cap since I've noticed a little coolant near the cap.

Coil pack was the first thing I ruled out. Not sure if it matters but my MIL only illuminates under hard acceleration, this is when I feel the misfire also. I guess it could be misfiring at other times even though the MIL doesn't illuminate.

C-ked

I found that once you've done all you can with plug changes, seafoam, and injector cleaner. The final and best option is to take it out on the freeway going 80mph for about 30 min to clean out the carbon.