Direct Injector Tests - Mercury 200 OptiMax Jet Drive Service Manual

Direct Fuel Injection
NOTE: Checking resistance on a direct injector while still installed in the engine can be difficult. An easy and fast way to make
resistance checks on direct injectors is to use service harness P/N 84‑879346A49. This harness is normally used as a service
replacement part for the direct injector connector if it becomes damaged, but also works well to test the injector when it is in place
between the cylinder head/block and fuel rail.
Red
Injector pin
Each injector pin
DMT 2004 Digital Multimeter
Direct Injector Harness

Direct Injector Tests

Direct Injector Leak Test
1. Attach the leakage tester kit to the discharge side of the direct injector.
2. Pump up the leakage tester to 172.4–206.8 kPa (25–30 psi).
3. The direct injector should not leak‑down more than 3.5 kPa (0.5 psi) in one minute. Replace the direct injector if it does not
meet the specifications.
a
Leakage Tester Kit
Direct Injector Ohm Test
Use the DMT 2004 digital multimeter to complete the following tests.
Page 3B-60
Direct Injector Resistance Test
Meter Test Leads
Black
Injector pin
Ground
15
20
10
25
5
30
0
Meter Scale
Auto
Auto
91‑892647A01
84‑879346A49
a - Leakage tester kit
b - Direct injector
b
10267
Reading (Ω)
1–1.6
> 1000
FT8950
90-8M0050731 MAY 2011