I've got an issue with my 96 A6 2.8. I'm getting a P0303 code and I've tried to sort it out but, I'm starting to get a bit worried. I've swap plug wires with no change. Replaced the #3 plug with a new plug and I've replaced the coil with a used model - no changes there either. When I disconnect the wire from the coil with the engine running the engine doesn't slow down like it does on the other cylinders however, I can see the arc jumping from the coil to the wire. I changed the oil to see if there was any anti-freeze in it but, it looks fine other than being overdue for a change. Last time I pulled the plug it was damp and black. I didn't smell it, though. #2 plug was dry. I'm considering replacing the ICM but, it seems odd that only one cylinder (and always the same) would be misfiring from a bad ICM. I'd like to try moving an injector from #2 to #3 and see what happens but, I've only worked on older fuel injection system (Bosch L-Jet on my 77 bus). I'm a bit nervous about the process and don't have the money for a Bentley right now. Any tips or other suggestions?

Take care,
Ken

 

you've done the rest now change the injector, you have to disconnect the fuel rail to get to it and its quite an easy job

 

Do I have to worry about priming the fuel line after I've swapped them? I've always heard that newer fuel injection systems can be tricky in that regard. Is there any easy way to check the spray pattern? How does the injector connect to the fuel rail?

Thanks,
ken

 

the fuel rail and injectors simply lock in with an O ring and the rail holds them down and in place you wont have a problem with pressure they will prime with the ignition ( electronic ) spray pattern is the problem its an intermittent fault and chances are its a sticking injector, you could put some fuel system cleaner in the tank it might clear the problem

 

Sounds easy enough. I'll try it out tonight. Is is possible to soak the injector in de-greaser (not completely submerged) for a while to try to loosen it up it that's the problem?

Thanks again,
Ken

 

no point in a degreaser it won free it, it needs power to it to open the injector and the right tools to clean it if your taking it out, best Wat is put what I said in the fuel tank and let the driving do the job

 

I'm not sure if it means anything but, I always have 2 P0303 codes. One is a fault and the other is pending. I don't understand why.

 

a pending code is a soft code error which means it could have been there all the time if you didn't clear it, clear the code and see if it comes back

 

It comes back every time I clear it.

 

first and cheapest is the injector you could switch them round and see if the problem moves with it and go from there but im guessing its a bad injector the common sense approach is the fuel system cleaner first