Audi Q3 Starting Failure Traced to Fuel Pump Issues

Having had a similar starting issue with my 2011 Audi Q5 2.0 TFSI, I understand your frustration. With some basic car repair experience, I initially tried diagnosing it myself when the dashboard lights would flicker during starting attempts. The engine start problems turned out to be a blown fuse in the ignition circuit. After multiple failed starts and unstable running, a workshop inspection revealed a defective 15A fuse that was interrupting power to the car electronics. The repair was straightforward, just a fuse replacement costing 52 Euro including diagnostic time. However, your symptoms sound more complex than what I experienced. To better assist, could you share: Are there any warning lights on the dashboard? Does the problem occur more often when the engine is cold or warm? Have you noticed any electrical issues with other systems? Has the check engine light come on? A proper diagnosis is important since similar starting issues can stem from various sources, from simple fuse problems to more serious ignition switch failures or fuel system issues.

Thanks for your detailed reply. Last service was done at 10500km just 2 months ago. The check engine light started flickering right after turning the ignition key but goes away once the engine is running. The starting issue happens mostly when the engine is cold, especially in the morning. No other electrical problems noticed so far. The starter motor sounds healthy when cranking. The workshop charged a standard diagnostic fee of 85 Euro but couldnt pinpoint the exact cause during their initial inspection. They suggested it could be the fuel pump or ignition coil pack, but want to do more thorough testing. Hoping to avoid unnecessary parts replacement and costs.

Thanks for the additional details. Since you mentioned cold starts being problematic and the check engine light behavior, this points more toward an ignition system issue rather than the basic fuse problem I encountered. In my case with the Q5, I later experienced similar cold-start symptoms which turned out to be a failing ignition coil. The flickering check engine light during key turn is a typical indicator. After replacing the faulty ignition coil for 180 Euro including labor, the starting problems disappeared completely. The ignition system testing should focus on: Scanning for stored fault codes during cold starts, Testing ignition coil resistance values, Checking fuel pressure during cranking, Verifying ignition switch signals Given the similarity of our engine types, I would suggest having them check the ignition coils first before moving to more expensive components like the fuel pump. The workshop can easily test the coils resistance values, which should help narrow down the problem without replacing parts unnecessarily. Just to rule out simpler causes, have you checked if the problem persists with your spare key? A worn ignition key can sometimes cause intermittent starting issues with the car electronics.

The symptoms you describe match my cold starting issues perfectly. The flickering check engine light during ignition key turn was exactly what I experienced too. I will ask the workshop to specifically test the ignition coils first, as this seems the most likely cause based on your experience. The good news is that an ignition coil replacement at around 180 Euro sounds much more reasonable than a fuel pump issue. I still have my spare key and will try that tomorrow morning to rule out any key-related problems with the car electronics. I appreciate you sharing the detailed testing steps. This will help me discuss the diagnosis more effectively with the workshop and hopefully avoid unnecessary parts replacement. Will update once I get the final diagnosis and repair completed. The starting issue needs fixing soon as I cant risk having the engine shut off while driving again.