Hey all,

I'm hoping someone on here can offer some advice. I did a carbon cleaning on my 2007 A6 Avant 3.2L (using THIS guide) the other week and have run into a problem. A couple of days after I finished the cleaning I noticed that the car had trouble turning over. It would start then the RPM's would bog way down, the car would shudder a bit, then it would return to normal.

In the two weeks since the problem has gotten progressively worse. Now the car starts, but then shudders for a minute or so of revving before finally returning to normal. When this ends it runs butter smooth and I have no more issues.

The problem only seems to occur when the car gets hot sitting outside. On colder mornings it fires up without a problem. I'd thought maybe I didn't hook a fuel line up tightly enough or something so took the upper intake off again and disconnected/reconnected the fuel rails again and reassembled everything. I also took the time to put in new spark plugs since they were coming due, but unfortunately neither of these things made any difference.

I would appreciate any help in finding the mistake(s) that I made.

 

Run a complete bottle of the concentrated lucas FI cleaner, PLUS 12 ounces of the regular lucas FI cleaner. Run through the whole tank of gas without refilling. try that out.. -- check with an unlit propane torch to see if there is a vacuum leak in lines or fittings.