EDI TSG-416, Service Manual

Page: 121 / 228

TSG ‐ 416 FUEL SYSTEM
04 ‐ 12
Diagnostic Charts
Perform the preliminary test before proceeding.
Engine Cranking but Will Not Start
Test Step Result Action to Take
1 Check fuel tank Yes
No
Fill or replace the fuel
tank. (Do not exceed
80% of liquid
capacity)
Go to Step 2.
Is fuel tank empty?
2
Check fuel valve
Yes
No
Slowly open the fuel
valve
Go to step 3.
Is liquid fuel valve closed?
3 Check the excess flow valve
Yes
No
Reset excess flow
safety valve

Close the main fuel valve

Wait for a clicking sound from
the excess flow valve
indicating the valve has reset

Slowly open the main fuel
valve
Perform prelim. Test
before proceeding to
step 4
Is excess fuel valve tripped and closed?
4 Check lockoff valve supply voltage
Yes
No
12 volts to lockoff
activation circuit is
open, shorted to gnd or
the GCP module is
faulty. Check wiring,
connectors and fused
for possible cause.
Go to step 5.

Key OFF

Disconnect lock off valve connector from
harness

Key ON

Using a high impedance DVOM, check for 12
volt supply at the harness connector
Is the voltage less than 11.5 volts?
5 Check primary fuel pressure to regulator
Yes
No
Fuel filter element may be
clogged, inspect and/or
replace the fuel filter. Lockoff
valve may be faulty, replace
the lockoff valve.
Go to Step 6

Verfiy that 120-180 psi is going to the regulator

Check downstream of the lock off valve

Key ON
Is the pressure not in the above range?
6 Check for icing or freezing of the regulator.
Yes
No
The presence of ice on the
converter without the engine
cranking indicated the possibility
of a fuel leak past the primary
sea of the converter
.
May be electronic, check that the
CAM and crank sensor are not
damaged and as well as all wiring.
Check if faults are present with the
GCP diagnostic software. Refer to
section 8, engine controls.

Key ON

Check for ice or frost build up on the converter
casing and outlet port

Key OFF

Is ice present?