Using a clip-on ammeter of motor tester, check actuation of injector. Clip-on ammeter must satisty the following conditions.
Measuring range ＞ 25A
Bandwidth ＞ 100kHz
Attach the plug to the injector. Fasten clip-on ammeter around lead to pin.2 of corresponding injector. Allow engine to be at idle.
Refer to the set value(current) as following figure.
Length of holding current phase (max.12A) is governed by engine speed, injection time and changes on velocity.
The first current curve shows the pre-injection.
Check the injector for injecting of fuel. As checking procedure, detach the injector plug from each boxes and connect to replaced injector.
If change to enine running results, injector is injecting. If no change to engine running results, injector is not injecting.
This test cannot however establish whether an injector is injecting an correct quantity.
If necessary, all injectors have to be replaced.
Measure the supply voltage at ECM pin 33(Cylinder #1 Injector), to pin 36 and pin 39(Cylinder #3 Injector), pin 40(Cylinder #2 Injector) to pin 37 with ignition OFF.
Set value : 0V
Check wiring if set value is not attained. If wiring is OK, replace the ECM.
Detach the connector from injector.
Measure the resistance between terminals.
0.3 ~ 0.6 Ω(at 20°C)
Connect the connector to the injector.
