Q: VW passat 2006 running car stopped all on a sudden. Battery full power, fuel > half tank, Fuel pump ok,mass flow no blocks

The place to begin when a car won’t start is to figure out what is missing. An internal combustion motor needs fuel, proper fuel pressure, spark, correct cam timing and compression to run.

Here are some items you will need:

• Spark tester

• Noid lights

• Fuel pressure gauge kit

• Compression gauge

You will need to check for the presence of all of these using the tools I have linked to above. There are a variety of different scenarios that can play out here. If you don’t have spark or injector pulse as indicated with a noid light, you should suspect a crank or cam sensor. Anything that allows the ECM to supply both spark and fuel is suspect.

You will need to find your fuel pressure specification in a shop manual to confirm it is operation properly. A fuel pump can fail due to power supply failure or the pump can fail itself. Banging on the bottom of the fuel tank while someone cranks the car is a valid test that makes fuel pump diagnosis easy.

Check compression in every cylinder. If some are significantly lower compression than the others, suspect a problem with camshaft timing. Follow that up with a timing belt inspection if the compression is off in some cylinders.

Once you find what is missing, you will need to follow that info up with some study to figure out what affects the failed system.

If you feel like you need some assistance with these checks and repairs, enlist a qualified mechanic who has the tools and experience to properly diagnose the cause of your stall.

Good luck.