CUMMINS N14 - FUEL DRAIN LINE RESTRICTION

Operate the engine at maximum horsepower RPM and
Advertised Horsepower.
Observe the reading on the gauge.
NOTE: The maximum fuel inlet restriction is as follows:
STC CELECT™
(plus ECM Cooling Plate)
Clean fuel filter: 102 mm Hg
[4 in Hg]
127 mm Hg
[5 in Hg]
Dirty fuel filter: 203 mm Hg
[8 in Hg]
228 mm Hg
[9 in Hg]
Correct the restriction or replace the fuel filter.
Fuel Drain Line Restriction
Use Pressure Gauge, Part No. ST-1273, to measure fuel
drain line restriction.
NOTE: Do not measure fuel drain line restriction with the
fuel measuring device installed. This will not measure the
drain line restriction of the vehicle’s return plumbing.
Hold the gauge at the same level as the connection.
NOTE: The gauge will not measure the correct pressure if
the gauge is not held at the same level as the connection.
Operate the engine at maximum horsepower RPM and
Advertised Horsepower.
Observe the reading on the gauge.
NOTE: The maximum fuel drain line restriction for STC and
CELECT™ is as follows:
With Check Valves: 165 mm Hg [6.5 in Hg]
Without Check Valves: 65 mm Hg [2.5 in Hg]
General Test Procedure - Chassis Dynamometer (8-06) Engine Testing
N14Page 8-44