Rainy day, so dropped in new spark plugs and Checked for codes with Vagcom.

Old plugs were NGK platinum OEM with 40K miles on them. Only light grey ash was noted, and the gap was correct, so essentially, there was no wear on the plugs.

No codes found and averaging 30 mpg.

Now if I could only find out why my car wont start if I fill up with the engine off.

 

What milage on your car? that is definately wierd if it wont start...

does it start everytime after leaving the gas station?

 

It is weird.

If I turn the car off and fill up, it wont start unless I either wait for 5 minutes or try to start it several times.

Otherwise it starts first time every time. If the engine if off and I open the gas tank without putting in gas it will start OK.

I[m thinking that there has to be something with evaporative emission system, but I find no codes. I'll keep looking.

 

are our fuel pumps internal? maybe the gas is shorting out the electronics in there, and it just takes a couple minutes for it to evaporate...just a thought

 

Poked around and found that one of the check valves on the evaporative system has been rubbing on a pieco of metal. Looks like maybe it has rubbed through, but it is hard to tell. I'll replace the valve and see if that fixes it.

 

have you tried starting it with the fuel cap off (after filling up)?

 

Interesting question. No I haven't.

 

I think if you start the car after filling up, without tightening the gas cap at least 3 clicks... it throws a CEL.

 

Sounds like the purge valve located on top of the air filter housing.

#3 I believe...

 

Possibly.

However, Check valve number 4 has been rubbing against a piece of metal and may be worn through. I've ordered a replacement and see if that helps. If not I'll try 3.