Detroit Diesel MBE 4000 Service Manual page 299

www.rtrucks.ru
Identify the cylinder with the biggest absolute value – highest positive or lowest negative. The
troubleshooting steps for both conditions are:
For Highest Positive:
1. Check torque at all the transfer tubes nuts (45 N·m [33 lb·ft]). Run the test again. If the
results are out of operational range, proceed to next step.
2. Find the cylinder with the result closest to zero. Swap the injector nozzle holder and the
transfer tube between this cylinder and the cylinder with the highest result. Run the test
again. If the highest result follows the injector nozzle holder, replace the nozzle holder.
If not, proceed to the next step.
NOTE:
After removing the injector nozzle holders and transfer tubes, check the coupling area
between both components and the seal rings. If any defect or damage is found, replace
the damaged parts.
3. Return both injector nozzle holders and transfer tubes to their original positions and run
the impact delay time and compression test routines.
For Lowest Negative:
1. Check torque at all the transfer tubes nuts (45 N·m [33 lb·ft]). Run the test again. If the
results are out of the operational range, proceed to the next step.
2. Find the cylinder with the lowest result, remove the injector nozzle holder and check the
opening pressure. If the pressure is lower than the minimum spec (275 bar [3989 psi]),
replace the injector nozzle holder. If the pressure is within the spec, proceed to the next
step.
3. Run a compression test using minidiag2, ProLink reader, or DDDL 5.0 (refer to the
Diagnostic Tool Manual for instructions to run this test). The readings must be 75% or
higher. For readings lower than 75%, remove the oil pan and cylinder head and check
for damaged components.
2.12.2.2
This test measures the reaction time of the unit pumps. The operation range is from 1.2 to 2.1
milliseconds. Perform the following troubleshooting procedure for values out of the operating
range:
1. Check the engine harness from the DDEC-ECU to the suspected unit pump – connectors
and wire. Look for bad or loose connections and broken wires. If there are none, proceed
to the next step.
2. Swap the suspect unit pump with one operating properly and run the test again.
Refer to section 2.1.1 for unit pump removal and refer to section 2.1.2 for unit pump
installation. If the condition follows the unit pump, replace the unit pump.
All information subject to change without notice.
6SE412 0403 Copyright © 2004 DETROIT DIESEL CORPORATION
www.rtrucks.ru
Impact Delay Time Troubleshooting
www.rtrucks.ru
www.rtrucks.ru
MBE 4000 SERVICE MANUAL
www.rtrucks.ru
2-53
www.rtrucks.ru