SEAT Workshop Service and Repair Manuals

Injectors: checking

Special tools and workshop equipment required

t	Hand multimeter -V.A.G 1526 A- or multimeter -V.A.G 1715-

t	Diode test lamp -V.A.G 1527 B-

t	Auxiliary measuring set -V.A.G 1594 C-

t	Test box -V.A.G 1598/18-

t	Current flow diagram

Checking conditions l  Hall Sender incorporated into ignition distributor, OK. l  Fuel pump relay, OK. Checking process   Caution The fuel system is under pressure. Before opening the system, place a cloth around the connection. Then release pressure by carefully loosening the connection. –  Remove air filter → Fig..

–  Unplug the connectors from the injectors -arrows-. –  Connect diode test lamp -V.A.G 1527 B- using aux. cables from -V.A.G 1594 C- to connector contacts of cylinder 1. –  Operate the starter.    The LED must flicker. –  Repeat check at the injector connectors for cylinders 2…4. If the LED does not light up on any cylinder:

–  Connect diode test lamp to cylinder 1 connector, contact 1 and earth. –  Operate the starter.    The LED must light up If the LED does not light up: –  Check wire between 2-pin connector contact 1 and fuel pump relay -J17- for open circuit using current flow diagram.    Wire resistance: 1,5 Ω max. If the LED flickers on one or several cylinders:

–  Connect test box -V.A.G 1598/18- to control unit wiring harness. –  Check the wiring for open circuits between test box and injector connectors, using current flow diagram.

Cyl.	Injector connector, contact	Test box -V.A.G 1598/31-, socket
1	2	7
2	2	6
3	2	28
4	2	4
Wire resistance: 1,5 Ω max.

–  Also check wires for short circuits to one another.    Specification: ∞ Ω –  Check wiring between connector contacts 1 of injectors for open circuit to one another.    Wire resistance: 1,5 Ω max. –  Also check wires for short circuits to one another.    Specification: ∞ Ω Checking resistance of injectors

–  Check resistances of injectors between contacts.    Specification: 14…17 Ω Checking spray pattern and leakage Special tools and workshop equipment required t  Auxiliary measuring set -V.A.G 1594 C-

t  Digital potentiometer -V.A.G 1630- t  Tester for checking injection flowthrough -V.A.G 1602-   Caution The fuel system is under pressure. Before opening the system, place a cloth around the connection. Then release pressure by carefully loosening the connection. Checking process –  Remove the triple connector from the ignition transformer.

–  Pull 4-pin connector -1- off the coolant temperature sender -G62-, -2-. –  Connect digital potentiometer -V.A.G 1630- using aux. cables from -V.A.G 1594 C- to connector contacts 1+3 and set connected side to 15 kΩ. –  Remove the following connectors, throttle valve control unit, oil pressure switch and intake manifold pressure sender, and separate the wiring harness for the intake manifold and the coolant thermostat housing. –  Remove fuel rail complete with all injectors from intake manifold (fuel hoses remain connected).

–  Hold a small container under the injector to be checked and pull connectors off all other injectors. –  Operate starter (a second person will be needed to do this) The injectors should issue pulses of spray following the order of ignition. –  Repeat check with the remaining injectors, ensuring that injector to be checked is the only one connected. –  Then check injectors for leaks. No more than 2 drops/min may leak out.   Note! Ensure that the O-rings are not damaged when installing the injectors.