Hello,
I am looking for a solution to my engine missing problem. lately it has been missing whenever there is a load on the engine, like acceleration, going uphill. When the missing starts, the CEL blinks, then goes out after the missing subsides.
If the vehicle is on level roads without the need for any more throttle, it operates fine, which is not very often here in hilly West VA.
Is it a vacuum leak, or an electrical problem? What is the best place to start looking. I do not have access to a VAGCOM.

Thank you for your help

 

If you truly want to tackle the problem and find out what is going on get a VAGCOM cable from Ebay for around 20 bucks (make sure it is compatible), then get the free software package and read out the codes. The details from VAGCOM are better then what you get from Autozone since it will read out fault codes that are more "hidden".

If you don't want to spend the money go to Autozone or someone who reads it out for free but don't expect a full blown out trouble code list. Also think about getting a different car if 20 bucks on a diagnostic cable is too much.

In addition:
Blinking CEL indicates misfiring which could be caused by numerous factors.

 

I recently had the timing belt and MAF sensor replaced approx 1-2 months ago. I had the coil packs replaced by Audi last spring. I just replaced the right valve cover gasket. After using 5W-30 oil for the last 3 years, I was recently getting a low oil pressure light, so I changed to Castrol semi synthetic 10W40 for high mileage vehicles. I went to Advance auto parts and used their code reader and here is what I got:
P0300-Random multiple misfire
P0305-cylinder 5 misfire
P0304- " 4 "
P0302- " 2 " (this one was also labeled as pending)
P0301- " 1 " (this one was also labeled as pending)

As for access to a Vagcom, I am in rural WV and the nearest Audi dealer or repair facility is over 2 hours away, so I used Advance's instead

 

If you're misfiring when the car is under heavy load, check into replacing your fuel filter. It's probably clogging up and can't flow enough fuel for heavy loads.

 

My first thought would be to revisit the belt replacement and look for something related to that work. Your timing may be retarded and this will reduce power under acceleration. This may mean that one of the tensioners is not tight enough and the belt is shifting. One of the tensioners is tightened by oil pressure, if this is low for some reason, this tensioner may be compromised. I would pull the front cover and verify that all the parts are working right and that the cams are timed right. When the missing happens, you have low vacuum under accleration, I doubt this would be a vacuum leak, this would afect high vacuum times more, such as at idle. One thing that old mechanics alweays say, high speed misfires are often plugs, are these okay?

 

I went and ordered a VagCom cable off of Ebay from a US seller with 100% positive feedback. I was reluctant to get one from Ebay before because I wasn't sure of their reliability and didn't have the surplus funds to order the much more expensive original cable/reader.
Well, when it gets here, I will read codes again and I will swap coils to known good cylinders and see if the codes follow to the suspected bad coil cylinders. I guess that will tell me if it is a bad coil.
As far as the plugs, I'm sure they have not been replaced so I will go ahead and put a new set in while I'm waiting on my cable to arrive.

 

Replaced all 6 plugs, gaped them at .040 and now no more missing or CEL. Thanks again for everyone's help and guidance.

 

Glad to hear it