My wife loves her 1999 Golf GT TDi It bumbles about getting 50-60 mpg however the other day she noticed the mpg has dropped to about 22mpg as she had to fill up mid week and puts the same amount of fuel in each weekend and intheory should be getting more for her money as the price of diesel has dropped a lot. Cant see a leak, its always had a cloud of black smoke when booting it but then it stops so could this be over-fuelling and if so any ideas why?
1 check air filter 2 Check all boost pipe fittings for leaks also check vacuum pipes 3 plug it in and check for faults then maf readings on measuring blocks 4 burn it
1 ok will do 2 ok will do 3 what are measuring blocks? 4 ok - will do if 1-3 above don't work Apparently an engine temperature sensor can cause issues however the gauge seems accurate
Forgot about the temp sensor temp sensor has two circuits one for ecu one for gauge this should show up as a fault on the vag com and can be checked on measuring blocks When you go into vag com engine hit measuring blocks then 03 for maf for readings But it could just be something as simple as your four pin temp sensor
If it's got climatronic, you can press ECON+cold+blower up and then press the heat controls (cold = up, warm =down) until you get to '45' which is engine coolant temperature.
