joekob

Hello Update on progress - still unresolved - here's a write up of steps taken thus far.... Skoda Yeti 2.0 TDI (Engine code CFHC, ECU 03L 906 018 QN) Symptoms: P0087 – Fuel Rail/System Pressure Too Low. Car drives normally at low load but enters limp mode under sustained load (typically after reaching ~80 km/h). Issue occurs from cold and warm. Parts Already Replaced (All Genuine or Quality Where Noted): Full set of fuel injectors (new genuine Bosch) High Pressure Fuel Pump (HPFP genuine bosch) Fuel Metering Valve (N290) Rail Pressure Regulator Valve (N276) Fuel Rail Pressure Sensor Fuel filter + lines flushed Battery (new) Cam follower / timing belt related components checked (good) Tank inspected and lift/presuppply pump checked and cleaned (had a very small amount of sudge - perhaps even silicon? - in it). Diagnostic Tests Completed: Injector return flow test: Normal (equal across cylinders) Static lift pump flow test: 2.4 L/min (good) Filler cap vent test: No improvement Multiple VCDS logs: Consistent rail pressure lag under load (150–350+ bar deficit) Cylinder 3 deviation improved after new injectors but rail pressure issue remains Current State of Play The high-pressure side (injectors, HPFP, sensors, N276, N290) has been completely renewed and tested. Static low-pressure volume is good, but the system still cannot maintain rail pressure under sustained load. Next steps - the tank pump is moving enough fuel (2.4L per min), but MAY not be performing under pressure/load. I havebeen advised to to do a manual pressure test on the fuel line between the filter and HPFP, and take it for a drive and trigger the P0087 error. It appears that a manual check is required as the ECU version and VCDS does not have a presupply pressure sensor, or if it does it not accessible via VCDS measuring values. The crappy thing with the manual test is that I need to rig a gauge from the engine bay to somehow read it from the drivers seat whilst travelling at 60kmh. Crazy. Happy to hear any other suggestions before undertaking the manual test!

Hi Have not actually checked but will do. For what it is worth I can tell you that the VCDS data suggests that it is below the expected pressure. Thanks!

Hello Has anyone managed to resolve this issue? Ive got a 2014 Skoda Yeti 2.0 Diesel. Replaced: Injectors Fuel Valve Fuel Filter (Fuel looked a bit sludgy...) Checked fuel tank pumps Car starts fine and drives around but goes into limp mode and glow plug lamp flashes. Can clear codes etc with VCDS but P0087 comes back again. VCDS suggests fuel pressure issue being pressure islower than expected value. Any help apreciated.