FUEL INJECTOR INFORMATION

TM 9-2320-364-20-1

2-14. DDEC III/IV TROUBLESHOOTING (CONT).

Section V. DIAGNOSTIC DATA READER INFORMATION (Cont.)

FUEL INJECTOR INFORMATION

Fuel Injector Menu Selections are defined as follows:

Cylinder Cutout

Response Times

View Injector Calibration

Update Injector Calibration

D.1 CYLINDER CUTOUT

The cylinder cutout function provides a test method to locate a injector whose pulse width output is different from the others.

This is done by cutting out one injector at a time and comparing the resulting injector pulse width with the no cut-out pulse width

established before the first cylinder was cutout.

Cylinder cutout test options:

(1) Run New Test or Review Last Results

(2) Select RPM Setting: IDLE or 1000 RPM

(3) Automatic Test or Manual Test

D.2 RESPONSE TIMES

The injector solenoid response times are defined as the time it takes from when the DDEC III/IV ECM requests an injector be

turned on to when the injector solenoid valve actually closes.

Injector response times generally increase with low battery supply voltage and decrease with high battery supply voltage.

Although injector response times vary from injector to injector at a given RPM, each individual injector response time should

remain relatively consistent from one firing to the next. Wide variations in response time (typically +/-- 0.2 msec) for one

injector at a steady RPM may indicate an electrical problem (faulty alternator or voltage regulator, poor or broken ground

cables, etc.).