Chrysler 1991 Service Manual Supplement page 115

14 - 18 FUEL SYSTEM
DIESEL FUEL INJECTION SYSTEM DIAGNOSIS
. CAUSE ACTION
Excessive fuel consumption
Improper diesel fuel
Use correct fuel for conditions. Refer to
owner's manual
Incorrect injection pump timing Adjust injection pump timing
Restricted or damaged injector nozzle Repair or replace as necessary
Clogged or restricted air filter Remove restrictions or replace air filter if
necessary
Injection sequence does not correspond
• with firing order
Install fuel injection lines in correct order
Intercooler internally blocked or leaking
Check pressure drop across intercooler.
If pressure drop is more than 4 in. Hg,
clean or replace as necessary
Low idle misadjusted
Adjust idle stop screw
Malfunctioning KSB valve Replace injection pump
Incorrect injection pump to engine timing Adjust injection pump to engine timing
Fuel injection pump malfunction or
not adjustable
Replace fuel injection pump
Unable to shut engine off
Voltage to fuel solenoid interrupted or fuel
solenoid inoperative
Correct voltage supply problem or replace
solenoid
Either poor performance, black
smoke or low power
Improper fuel Drain fuel tank, flush system, fill with .
proper fuel for conditions. Refer to owner's
manual
Air in fuel system Bleed fuel system
Intercooler internally blocked or leaking Check pressure drop across intercooler.
If pressure drop is more than 4 in. Hg,
clean or replace as necessary
Restricted or blocked fuel injection lines Remove restrictions or replace lines
Incorrect injection pump timing Adjust injection pump timing
Restricted or damaged injector nozzle
Repair or replace as necessary
Clogged or restricted air filter Remove restrictions or replace filter if
necessary
Air fuel control tube leaking or broken Repair or replace as necessary
Low manifold pressure
Check and repair turbocharger operation
Injection sequence does not correspond
with firing order
install fuel injection lines in correct order
Low or uneven engine compression Repair as necessary
J9114-255