(Thursday, Friday and yesterday)... I finally got around to fitting a new set of injectors to my FSI. The parts had been sitting in their boxes starring at me forlornly from the top of the chest of drawers in my bedroom since I bought them back in April, along with a set of new o-rings. I'd had a persistent misfire on cylinder 4 at idle, causing occasional EMLs and associated DTCs stored in the Pro Boost ECU supplied by
@A2Steve. I'd been trying the various things recommended in the excellent
misfire struggle thread but concluded this was the next move.
Really happy to say the misfire is gone, (I even get a set of 4 zeros on the misfire count in VCDS measured values) the throttle response is now really good, drives
so much better, no flat spot, smooth idle. My daughter drives the car to school and back every day, but not during half-term this past week, and she can tell the difference too. So, after about 20 miles of test drives, there are no DTCs in the ECU. I might even swap back to the original ECU temporarily to see if drops into lean-burn without DTCs / EML just for a laugh and see if the fuel consumption etc. improves
How long did it take? Try not to laugh: about 14 hours, even taking a few short cuts. I had started after lunch on Thursday and worked until after midnight then a couple of hours on Friday night after work and then yesterday (Saturday) morning.
The Elsawin instructions for intake manifold removal are pretty poor. They tell you to do some things that aren't strictly necessary, for example they say to disconnect rubber fuel hose or coolant hose from parts that can be unbolted and moved to the side with the hose still connected. At the same time they neglect to tell you to do one essential thing which is disconnect the combined oil filler / dipstick tubes at the sump - if you don't do this then the tubes will probably break when you drop the engine the ~3" required to gain the space to get the upper manifold out.
There were some close-calls with almost cross threading fasteners, including the intake elbow support screws downstream of the throttle body, the two screws underneath the upper intake manifold where the support bracket attaches and most disturbingly, the high pressure fuel pipe union at the fuel pump. Really this short section of metal pipe is a fiddle. Next time I would only disconnect the union at the fuel rail end and withdraw the pipe together with the (still connected by its hose) complete fuel pump in the same direction towards the nearside. This then allows the metal pipe to be renewed if required and the steel union screwed into the fragile aluminium thread on the fuel pump in full view rather than risking cross-threading it like so nearly happened to me.
All the best folks!
Matt
Matt