Fuel problem

[eddy]

So I have the 2.0 q5 flex fuel model. Because of gas prices I’ve been taking advantage in using e85 also is easily available around me. In the manual it says every 5th fill up use 91 octane. And I’ve been doing that however I’ve been noticing lately that when I use 91 my q5 starts acting up. It struggles to start. After using up the 91 and I go back to e85 it goes back to normal. I don’t get any codes related to this. I do have a check engine but is for intake manifold runner position sensor/switch circuit p2015. Has anyone gone through this or have any idea why it might be happening? Any help is appreciated


Sent from my iPhone using Audizine Forum

[StuckAntichris]

The runner position switch code could very well be your problem. I have not personally experienced this issue but if the car does not know where the flaps are it could be trying to have it run rich/lean on startup.

There is a 5th fuel injector right behind the throttle body that only activates when the fuel has above a certain % of alcohol. The reason you could be having starting issues is because the flaps arent closing enough to start when using 91.

I would look into replacing the sensor Part #(07L 907 386) and worst case you will have to replace the whole plastic assembly, Part #(06H 133 209 G). Also check out this part diagram Link

A word of warning if you end up having to replace the entire plastic assembly, if when you pull the assembly a fuel injector comes out with it, you will need to replace the white seal on the end of it. Part #06J-998-907-B. This does require a special tool but if you ask nicely at the dealer and or an independent shop they should be able to replace the seals for a nominal fee if you bring the parts. You'll need one kit per injector.

Finally if you need more help the B8 A4 forum gets a bit more traffic than this one and that forum also has more 2.0T information. Feel free to ask your questions in there. Just provide your year in your description of the vehicle.

Hope this helps!

[eddy]

Thanks for great info. It makes sense that could be the root of all my problems. I will replace the sensor and go from there. I’ll let you know what happens


Sent from my iPhone using Audizine Forum