Hi everyone, I'm a first-time Audi owner. I recently bought a used 1998 Audi A6 Quattro (2.8L).
Every time I fill it up with gas the car has trouble starting and runs rough for a minute or so afterwards. This has happened since I first bought it a few months ago.
It takes about 10 to 15 seconds of holding the key in the 'start' position before the engine finally comes to life. After that, it runs rough for a minute or until I rev the engine for a few seconds.

Other symptoms that I have:
- The check engine light has been on since I first bought it.
- The inside smells of gas most of the time and always smells of gas for at least a few days after filling the tank.
- The outside sometimes smells of gas. If I had to guess where, I'd say it smells most toward the front of the car. I can't work out what the pattern is for when it does and does not smell outside. Right now it's a bit less than 3/4 full and it's been maybe a week since I filled it, and it smells inside and out.
- I don't have any problems filling the tank. Some people with similar problems have said the automatic filling machines stop and start when filling, but mine fills just fine. I've also never overfilled it (I don't "top up" after the auto pump switches off).

One thing I've noticed is that one of the hoses that attaches to the purge regulator valve (N80 valve, I think it's called) has had the clamp on it cut off. The hose has simply been reattached with the cut clamp hanging fairly loosely on it.
Because of this, I'm wondering if the previous owner tried to fix the problem and did a bad job of it. Perhaps he didn't replace the charcoal canister or perhaps having the N80 hose loosely attached is causing these problems?

I really don't have the money to take it to a mechanic and I usually work on my cars myself anyway. But I'm new to Audis, so I'm hoping that I can find what I need here. I'd greatly appreciate any assistance.


My main questions are:

1) Does anyone know what the cause of these problems would be? If not, is there some more information I can give that might help to diagnose the problem?

2) I'm sure that the N80 valve hose being essentially unclamped is bad, but could it be causing some or all of the problems I'm seeing? Could it have caused any further damage?

3) Should I buy one of those code readers that some people have? Do I need it to diagnose the problem? If I fix the problem, do I need some special device to make the check engine light go away?

Thanks very much for any help.


I just read the "Noobie" thread, so I'm adding more information:
It has an auto transmission, 180k miles and has apparently been serviced regularly according to the previous owner (though the logbook does not note any for past 80k miles or so - but there is a sticker on the windshield which notes that it was serviced recently and needs to be serviced in 1k miles). Also, I have no owners manual for it, unfortunately.

 

Read the 'gas odor" sticky to start with

 

I've read through that thread - when I first wrote my post I mentioned it, but when I clicked "submit" for some reason it logged me out, so I had to type the whole thing out again. I forgot to mention it again in the new post that I wrote.

I was initially worried that I had the same problem as mentioned in the "Gas odor" thread, but the smell seems to be coming from the front and I don't think I have all the same symptoms necessarily. It might be the problem of course, but I thought I should post everything that I notice is wrong in the hopes that someone might be able to confirm whether or not that is the problem.

 

I have the exact same car that you have and had a profound gas odor. I too went through the "sticky" advice just to be sure. I looked for a traditional gas leak under the car continually and didnt find it. I then went to my mechanic and he put it on the lift and found the gas line about a foot in front of the tank was leaking. Why it never visually dripped is still a mystery but I decided to replace the entire line just to ward off more of the same. If you haven't had your car in the air that might be the next step. And yes, get a VAG code reader, you can get a pretty good deal on the web and mine has become invaluable since audi is "sensor happy" My check engine light has been on for years and the car runs fine. Ive come to interpret that light as indicating the engine is currently running. :-)