SEAT Workshop Service and Repair Manuals > Leon Mk2 > Power unit | 4-cylinder diesel engine (1.6 l 4V, TDI Common-Rail) | Fuel preparation system Diesel injection | Filling / bleeding / checking the diesel direct injection system | Checks on injectors (engine does not start) | Checking return flow rate of injectors Condition: (Engine will not start)

Checking injectors with vacuum > < Checks on injectors (engine does not start)

Checking return flow rate of injectors Condition: (Engine will not start)

Checking return flow rate of injectors Condition: (Engine will not start)

Note

t	Leaky regulating valves in injectors may lead to irregular engine running or may prevent engine from starting.

t	To check regulating valves for soiling (and with it higher leakage), further to the "classical" return quantity measurement, checking with vacuum is also possible.

t	Observe instructions for working on fuel system → Chapter

»Carry out the following work sequence«

–	Open return line connection -3- of injectors to be tested at the fuel return pipe using a small screwdriver and long-nose pliers.

–	Collect escaping fuel with a cleaning cloth.

N20-10829

0.5 bar fuel low-pressure system:

–	Seal open return line connection with a blanking plug -arrow-.

–	Measure during engine start with starting speed ≥ 230 rpm.

l	Specification: Return flow rate 0 ml

l	Droplets are allowed

l	If a flow rate can be measured, at least one injectors is faulty.

–	Check injectors with vacuum → Chapter.

N23-10478

Power unit
4-cylinder diesel engine (1.6 l 4V, TDI Common-Rail)
Fuel preparation system Diesel injection
Filling / bleeding / checking the diesel direct injection system / ecks_on_injectors_(engine_does_not_start)/">Checks on injectors (engine does not start)
Checking return flow rate of injectors Condition: (Engine will not start)

Checking injectors with vacuum > < Checks on injectors (engine does not start)