VW Polo Rough Idle & Stalling Points to Fuel Sensor

Had nearly identical symptoms with a 2017 Golf TDI. The rough idle, stalling and jerking during acceleration pointed to fuel delivery problems. The check engine light triggered due to inconsistent fuel pressure readings. After diagnostic testing, the fuel pressure sensor showed erratic readings. The main issue was a damaged wiring harness connection to the sensor, the cables had worn through due to engine vibration. The protective sleeve deteriorated, allowing moisture to corrode the connection. This created irregular signals to the engine control unit, causing the fuel pump to deliver inconsistent pressure. When left unfixed, this can potentially damage the fuel injectors and reduce fuel economy significantly. The repair involved replacing the complete sensor assembly and harness. Getting the proper diagnosis was crucial, the symptoms could be misdiagnosed as fuel pump or injector issues, leading to unnecessary part replacements. Based on the symptoms described, recommend having the fuel pressure sensor connections checked first. While not catastrophically urgent, postponing repairs risks more extensive fuel system damage.

Wow, reading this really hits close to home. Had the exact same symptoms on my 2018 Polo, rough idle, jerking, the works. Got it fixed about 6 months ago with a new fuel pressure sensor and wiring. The diagnosis matched what was mentioned above. The fuel delivery system was getting wonky readings, throwing everything off. Cleared right up after the repair though. Just curious, what did the repair end up costing you? Mine came to around 450€ including parts and labor. Also wondering if youve noticed any other issues pop up since the fix? My fuel economy actually improved quite a bit after getting it sorted.

Great to hear back about your similar experience. Just got mine sorted last week and can confirm it was exactly the fuel pressure sensor acting up. In my case, the mechanic found a faulty cable connection that was causing those erratic readings and the rough idle issues. The repair was actually more straightforward than expected, only needed to fix the cable connection rather than replace the entire sensor unit. Total cost came to 95€, which seems like a bargain compared to your full sensor replacement. Since the fix, the engine runs perfectly smooth with no signs of engine misfire or stalling. The check engine light is gone and fuel economy has definitely improved. The erratic fuel pump behavior completely disappeared once the proper signals were restored. Been keeping an eye on things, but no other issues have surfaced in the past week. The diagnostic really saved me from potentially more expensive repairs, shows how important it is to catch these fuel system problems early.

Thanks for all the feedback. Finally got around to getting my Polo checked out yesterday. The mechanic confirmed it was indeed the fuel pressure sensor causing the trouble. Found corroded wiring just like you mentioned. Repair bill came to 280€ total, not as cheap as just fixing the connection, but better than a complete sensor replacement. They cleaned up the connections, replaced the damaged wiring section, and added extra protection against future wear. The difference in performance is night and day. No more rough idle or stalling, and the jerking during acceleration is completely gone. Even noticed the fuel economy has improved already. The check engine light cleared up right after the fix. Really glad I asked here first instead of just letting the shop guess at the problem. Could have ended up paying for unnecessary fuel injector or pump replacements. Will definitely keep an eye on how things run over the next few weeks, but so far everything feels back to normal.