DMitch16
22-11-2016, 12:57 AM
I have a dilemma - had a 2nd oil pump key failure but although engine survived, turbo was damaged. Drove the car for a few weeks whilst I sourced a remanufactured unit. Old turbo had slight whine, shaft was fairly loose with probably damaged bearings / seals but performed reasonably well considering and car returned a decent 42mpg average still.
Changed the turbo and tandem fuel pump, renewed the oil feed pipes, all seals and filters. Also changed front struts, top mount bearings and wishbone ball joints. Since doing that my 34 mile run to work averages 36mpg instead of a previous 40mpg. The downhill run home gets 38 to 40mpg instead of the previous 44 to 48mpg (gallop to work, canter home).
Where has my 4 to 8mpg gone?? Car has new parts, tracking is good, ride nice and tight, tyre pressures always right and I was actually expecting some improved mpg, especially as diesel prices have risen in the past few months.
Where do I start, what can I do or adjust on a PD engine where the ECU controls part of the fuelling process to recover my mpg whilst retaining the liveliness of the engine? Any adaptation or basic setting items that could be run?
No faults on VCDS scan but fuelling at 10mg/str at idle which is too high. Injection Quantity deviation pretty good, all cylinders pretty much even with values not usually over -/+1.0 at idle. Torsion value is high on the timing (well over +3 kw).
Changed the turbo and tandem fuel pump, renewed the oil feed pipes, all seals and filters. Also changed front struts, top mount bearings and wishbone ball joints. Since doing that my 34 mile run to work averages 36mpg instead of a previous 40mpg. The downhill run home gets 38 to 40mpg instead of the previous 44 to 48mpg (gallop to work, canter home).
Where has my 4 to 8mpg gone?? Car has new parts, tracking is good, ride nice and tight, tyre pressures always right and I was actually expecting some improved mpg, especially as diesel prices have risen in the past few months.
Where do I start, what can I do or adjust on a PD engine where the ECU controls part of the fuelling process to recover my mpg whilst retaining the liveliness of the engine? Any adaptation or basic setting items that could be run?
No faults on VCDS scan but fuelling at 10mg/str at idle which is too high. Injection Quantity deviation pretty good, all cylinders pretty much even with values not usually over -/+1.0 at idle. Torsion value is high on the timing (well over +3 kw).