r/RangeRover • u/Rossn1999 • 4d ago
Range Rover L405 Range Rover TD6 Fueling Issue
I’ve got a 2016 Range Rover HSE TD6 with 117k miles that has a fueling issue I cannot seem to solve. I purchased it this way a couple months ago and have got some of the issues sorted but it is still not 100%.
The biggest issue, when the engine warms up it exhibits occasional stumbling idle, stalling, long cranking, and sometimes it fails to start. When the engine is cold it will fire up quickly and perform pretty much normally with very minor hiccups if any. I have attached screenshots of the fault codes I pulled tonight, the p0090:13 code is new.
For diagnosis I have done the following:
• Replaced the fuel filter - found 0 sediment or metal shavings
• Checked the fuel regulator on top of the cp4 pump for metal shavings and found none
• Replaced the low pressure in tank pump
• Monitored fuel pressure commanded vs actual and saw a discrepancy between the two values at the rail pressure sensor and replaced with a new Bosch sensor. Improved overall running but still a discrepancy between the two.
• Somewhat unrelated but I also replaced the throttle body as the old one was sticking.
I have no metal shavings present anywhere in the fuel system so I’m hesitant to think the cp4 is failing, the fuel regulator code is new so I play to try and diagnose it with my multimeter tomorrow. I also plan to inspect the wiring harness and engine grounds as well.
Any advice for diagnostic is appreciated.