UK-POLOS.NET - THE VW Polo Forum

Hello!

After being a Mk4 golf fan I decided to buy a Polo as a project.. But I need some technical help please!!!

I bought a 2011 1.2 TDI blue motion with slight front damage (cracked front bumper/headlight clips to be repaired and front carrier/impact absorption bar, slight damage) I apologise in advance for War and Peace but feel I need to get all details across for this forum to be able to help!!

The battery was completely flat and not charging so I've bought a new battery recommended for this vehicle. After much cranking the engine rang at rough idle for about a minute then stalled. It turns over well but will not start.
After studying forums and manuals, I went down checking the fuel route.. fuses ok, 449 relays tested with 12v and multimeter- ok, hardwired fuel pump in tank 12v - whirred. BUT.. The fuel priming system cannott be heard starting when the key is turned and I haven't been able to register any voltage from the pump multiplug but this might just be my lack of electrical diagnosis skills..

New fuel filter was also fitted but fuel was pulled through already filled filter using vacuum pump until I was positive I had exceeded the filters capacity and was now drawing fuel through the lines. There were air bubbles in the lines I noticed.. but my mk4 golf had this too, so not overly concerned. injector 3 was cracked and engine cranked.. no fuel at injector. all injectors cracked.. still no fuel.

I have since used a generic OBD reader and produced 2 codes...

P0202 Injector Circuit Malfunction Cylinder 2
P0641 Sensor Reference Voltage "A" Circuit open

With my description and these codes Im hoping a technical mind out there can put me out of my misery and help get this vehicle running!!

Thanks in advance..
Matt

sounds like injector 2 is malfunctioning. if you have the opportunity, switch 1 with 2 or 2 with 3 to see if the DTC changes. if so, move injectors back and replace #2
see if P0641 also disappears. check all the fuses anyway as well.

I'm away from the car for a few days but I'll make that my next check! Thanks! Do I need any special tools to remove an injector? I've heard they may be coded.. does that pose any problems moving the injectors around?
Also if no.2 injector is faulty, will recoding be required??

sorry... if No.2 needs replacing will the new injector require recoding...?

i have no clue about how to remove an injector and given that they cost just shy of 1000 euros new I'd probably consult an expert if you don't know what you're doing.
they're quite fragile once removed.

and yes you need a diagnostic tool that's capable of adapting the new injector (long code written on the injector for the injector characteristics).

ok...
time to consult a VW specialist garage then...

Thanks for the advice.. !

iichel.. if I can pick your brains a bit further... if the original injector is removed and refurbished, would this still require recoding? im more competent mechanically than electrically so am happy to remove injector with Haynes manual and VW tool assistance, but the coding of the injector is where im stumbling...

yes, refurbishing will likely also influence the injection characteristics. but the question is, whether the refurbisher will be able to measure a new calibration curve.

Hi did you manage the find the problem I’ve had the exact same problems

Your injectors will get a new code after refurbushing.