We recently had a 2014 Golf R in the workshop with running issues and both lean and rich mixture faults . After elimination external mixture control and seeing that the engine management could not control the mixture via fuel trim and having seen multiple injector issues on these engines we decided to remove and test both the port and GDI injectors in our Asnu injector bench . The port injectors had intermittent spray patterns and one injector that would lock open .
Next we tested the GDI injectors and these too had poor spray patterns . Inside both the port injectors and the GDI injectors was something that we haven’t seen before small black particles that looked like rubber . Checking TPI information revealed that there has been an issue with ethanol fuel attacking the rubber fuel hoses on certain models and there is a revised \ modified new version that is resistant to the higher content ethanol fuels . The degrading pipes deposited small rubber particles that had found there way through the high pressure pump and into both sets of injectors .
The solution required the new modified rubber supply pipes , a new high pressure pump and all new port and GDI injectors . In conclusion if you have a Golf TFSI its worth checking if it has the modified rubber pipes fitted also where you can use E5 and no E10 fuels to reduce the risk of damage to injectors both the plastic filter baskets and also the rubber pipes .
