Hello all. Desperately seeking some good advice on a nagging problem with my Audi. Starts always without problems. After perhaps 5 kms the engine starts "hopping" and choking and progressively I lose response at the peddle. Sometimes I can drop the gear and hit the gas to get a marked response, but if I slow down the engine does not respond again. Usually little black smoke and always very rich exhaust. In most cases, the car comes to a standstill and is unable to be recovered, and finally "dies". I must wait around 5 minutes before starting the car again, at which time is tough to get going, and usually works by pumping furiously on the gas, or simply dropping it to the floor. Once up and running again the engine responds normally, but the same problem can occur again after a while. Seems to always occur on or during a slow, long and mild uphill section.
I seek advice because I have now taken the car to three (3) alternative mechanics, and have not even received good advice about where the problem lies. They simply do not know until the car breaks down for once and for all. In the meanwhile I am forking out money for servicing and in the end not getting a solution.
I live in a very cold part of mid-north Sweden, where winter temperatures can fall to minus 20. The climate here is fairly dry. I have had a motor warmer fitted in order to hold the temperature even, but this problem started to occur well beforehand, and during the summer here would occur particularly when the humidity was high.
Any idea and advice? If I can just get a start point in where to look I have a better chance than I do now.
Many many thanks in advance