196 5 HARD START AND NO START DIAGNOSTICS
Figure 247 Ground to terminal on cowl
CAUTION: Do not leave the IPR valve energize
d
longer than 120 seconds — this can damage th
eIPR
valve.
9. Apply B+ volts and groun d to the IPR v al
ve. Listen
for air leak in crankcase.
10. Record results on Diagnostic Form.
• If the IPR valve is energized, the air l
eak
should stop.
• If the air leak does not stop, replace the IPR
valve following the procedures in the Engine
Service Manual. Repeat test 14.3 - IPR and
High-pressure Pump Operation.
• If the air leak stops the IPR is functioning.
The high-pressure pump is suspect because
injection control pressure does not increase.
Continue with next step.
11. Remove the high-pressure pump following
procedures in the Engine Service Manual
• If high-pressure pump gear is loose, tighten,
and reinstall high-pressure pump. Retest
injection control pre ssu re .
If ICP pressure is still below specification,
replace the high-pressure pump.
• If high-pressure pump gear is tight, but the
high-pressure pump cam does not rotate,
suspect damage in the high-pressure pump.
Replace the high-pressure pump and test.
Note: To inspect high-pressure pump cam,
the fuel pump must be removed.
EGES-270-1
Read all safety instructions in the "Safety Information" section of this manual before doing any proced ures.
Follow all warnings, cautions, and notes.
©August 2008 Navistar, Inc.
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