My girlfriend's Audi A4 Quattro 1.8T Auto is stalling out every now and then. It's like it sputters and then sometimes she can rev it and it'll be OK. Other times it stalls and she has to restart again.

If at a stop, it can stall completely out. If at speed, the car has jerked for a moment and then been OK.

What I'm needing is what I can check. I'm thinking fuel pump is about to go out (it has 150k miles), or possibly a crank position sensor?

Has anyone had this problem? Or can someone tell me how to check the fuel pump or other possibilities? Fuel pump relay maybe?

I have a feeling we won't know until it just stops and leaves her stranded one day, which I really don't want to happen! Help?

 

your thinking too hard. start by looking for air intake leaks. fuel pumps either work or dont, there isnt much of a grey area when they are starting to go. they just stop. get a boost gauge, atleast a temporary one and it will tell you whats happening. you should be pulling around 25 pounds of vac at idle, and if stock, boosting to around 8psi at WOT. if your vacuum is higher then that there is a leak.

 

Thanks for the prompt reply. I forgot to mention how sporadic the stallout is. It's not like it's running poorly all the time and then deciding to stall out/stutter. It's very random, doesn't matter the temp outside, what type of driving, etc.

I may be wrong but I'm thinking a vacuum leak would be more consistent, thus able to detect?

 

maybe just the fuel filter instead of the pump. Could be the MAF as well. No codes through any of this?

 

No codes. The check engine light hasn't come on, which really surprises me, b/c I would know where to go from there. I'm gonna make sure the light comes on when it starts today in check mode, to make sure the bulb isn't blown out or something silly.

Oh, and I replaced the fuel filter a few months ago. I'll never forget that pain in the butt! Having to unstrap the gas tank and pull it down to reach the fuel filter sucked!

 

You could have a code without a check engine light. Have it scanned with a vag-com and you should save some time diagnosing the the car. I would include ECT sensor in the list of possibilities.

 

Its your MAF, I have the same year and model. Just fixed it for $275 installed. Finally!