Skoda Workshop Service and Repair Manuals

Testing injection valves Test control Special tools and workshop equipment required t  Test box -V.A.G 1598/22- t  Hand-held multimeter -V.A.G 1526 A- or multimeter -V.A.G 1715- t  Voltage tester -V.A.G 1527 - t  Measuring tool set -V.A.G 1594 A - t  Current flow diagram Test conditions l  Hall sender o.k. l  Fuel pump relay OK Test sequence –  Remove air filter → Fig..

–  Disconnect the plugs from the injection valves -arrows-. –  Connect with the adapter cables from -V.A.G 1554 A - the voltage tester -V.A.G 1527 - to the contacts of the plug for cylinder 1. –  Activate the starter.    The LED must flash. –  Repeat test on the plugs for the injection valves on cylinder 2...4. If the LED does not light up on any cylinder:

–  Connect the voltage tester to the plug on cylinder 1, contact 1 and earth. –  Activate the starter.    The LED must light up. If the LED does not light up: –  Check the cable between the 2-pin plug contact 1 and the fuel pump relay -J17- for open circuit according to the current flow diagram.    Cable resistance: max. 1.5 Ω If the LED does not light up on one or more cylinders:

–  Connect test box -V.A.G 1598/22 - at wiring loom to the 1AV control unit. –  Check wiring between the test box and the plugs from the injection valves for open circuit according to the current flow diagram.    Plug on cylinder 1, contact 2+bush 3    Plug on cylinder 2, contact 2+bush 80    Plug on cylinder 3, contact 2+bush 58    Plug on cylinder 4, contact 2+bush 65    Cable resistance: max. 1.5 Ω –  Also check the wires for short-circuits.    Specified value: ∞ Ω –  Check wiring between the contacts 1 of the plugs for the injection valves for open circuit.    Cable resistance: max. 1.5 Ω –  Also check the wires for short-circuits.    Specified value: ∞ Ω Testing resistances of the injection valves

–  Test the resistance of the injection valves between the contacts.    Specified value: 14 to 17 Ω Testing jet formation and tightness Special tools and workshop equipment required t  Measuring tool set -V.A.G 1594 A - t  Digital potentiometer -V.A.G 1630- t  Injection rate tester Test sequence –  Disconnect the 3-pin plug from the ignition transformer.

–  Unplug the 4-pin plug -1- from coolant temperature sender -G62--2-. –  Connect digital potentiometer -V.A.G 1630 - with adapter cables from -V.A.G 1594 A - to contacts 1+3 of the plug and set the connected side to 15 kΩ. –  Disconnect the plugs from the throttle valve control unit, the oil pressure switch and the intake manifold pressure sender and unclip the wiring loom at the intake manifold and coolant regulator housing. –  Completely remove the fuel distributor with all the injection valves from the intake manifold (the fuel hoses remain connected).

–  Hold a small vessel under the injection valve to be tested and disconnect the plug from the other injection valves. –  Have a 2nd mechanic actuate the starter. The injection valve must emit a pulsed jet of fuel. –  Repeat test at the other injectors. Make sure that only the valve to be tested is connected. –  After this inspect injectors for leaks. No more than 2 drops/min may trickle out.   Note When installing the valves, pay attention that the “O”-rings are not damaged.