TECH TIP
VW Golf Cranks, Does Not Start, Low Fuel Pressure
Nov. 01 2023
Nov. 01 2023

Vehicle: 2015 Volkswagen Golf (AU1,) L4-1.8L Turbo (CXBA), Manual Transmission/Transaxle

Mileage: 95,879

Problem: This VW Golf was towed in for a cranks/does not start concern. The vehicle owner admitted to modifying the vehicle (including a software tune in the ECM), but those modifications were performed quite a while before this issue started.

Case Details: The technician’s initial checks revealed that the fuel pressure from the high-pressure fuel pump (HPFP) was only 145psi (should be 1500psi when cranking/starting). The low-pressure pump (LPFP) was delivering 70psi (within specifications). The technician replaced the HPFP, but it made no difference. The pressure remained the same.

The technician looked for signs of fuel in the crankcase. There was none. There were no diagnostic trouble codes (DTCs) either. There should have been some DTCs set. NOTE: It's assumed the tuner software was responsible for that.

The technician decided to inspect the HPFP roller tappet. It was okay, as was the lobe in the vacuum pump that actuates it. However, he found the end of the exhaust camshaft was broken where the mating surface for the vacuum pump contacts it.

Confirmed Repair: Replacement of the exhaust camshaft got this Golf running again Fixed!

 

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