46
TK 56433-5-MM-EN
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c. The current through the pull-in coil should be 26
to 32 amps at 76 F (24 C).
N
No
otte
e:: The current specifications above are for
measurement at 76 F (24 C). If it is not
possible to measure at room temperature,
use the following table as a guide for the
expected current:
Temperature
Pull-In Coil Current
Low End
High End
-25 F
-32 C
31.8 Amps
38.9 Amps
-10 F
-23 C
30.8 Amps
37.7 Amps
0 F
-18 C
30.4 Amps
37.2 Amps
25 F
-4 C
28.7 Amps
35.0 Amps
50 F
10 C
27.2 Amps
33.2 Amps
76 F
24 C
26.0 Amps
31.8 Amps
100 F
38 C
24.9 Amps
30.4 Amps
125 F
52 C
23.3 Amps
28.4 Amps
150 F
66 C
23.3 Amps
28.5 Amps
d. If the current is out of specifications, examine
the circuit (fuses, relays, wires, etc.) for faults. If
the circuit is OK, proceed to “Fuel Solenoid
Replacement” (below).
e. If the current is within specifications, proceed to
step 8 for a visual check.
8. Visual functionality check (no measurements
required).
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a. Using the microprocessor keypad, energize the
fuel solenoid circuit for 4 seconds. Turn off.
Repeat ten times.
b. During each of these cycles, watch that the fuel
solenoid plunger retracts completely and stays
retracted until you de-energize the circuit.
c. If the fuel solenoid plunger fails to actuate or
hold during this test, check that the circuit is OK.
If it appears normal, proceed to “Fuel Solenoid
Replacement” (below).
Fuel Solenoid Replacement
1. Disconnect the fuel solenoid wire connector from
the main/unified wire harness and remove the old
fuel solenoid.
2. Connect the new fuel solenoid wire connector to
the main/unified wire harness.
3. Press the ON Key to turn the unit on.
4. Use the microprocessor keypad to enter the
Interface Board Test Mode. Refer to the appropriate
Microprocessor Diagnostic Manual for specific
information about the Interface Board Test Mode.
5. Perform a visual functionality check per step 8 in
“Testing the Fuel Solenoid” above to verify the fuel
solenoid operates correctly.
6. Energize the fuel solenoid by energizing the run
relay with the Interface Board Test Mode.
N
No
otte
e:: The fuel solenoid must be energized when it
is installed. If not, the plunger and the linkage
may not line up correctly and the fuel
solenoid will not function properly.
7. Place the O-ring in the groove in the end of the fuel
injection pump. Make sure that the O-ring is
positioned correctly during installation to avoid
damage and leaks.
Figure 40.
Fuel Solenoid Components
1.
Fuel Solenoid
2.
O-ring
3.
Groove in Fuel Injection Pump
8. Install the new fuel solenoid.
9. Press the OFF Key to turn the unit off after installing
the fuel solenoid.
Trochoid Feed Pump
The TK486V25X engine has a trochoid feed pump on
the fuel injection pump. The trochoid feed pump
supplies fuel to the injection pump at a pressure of 65
to 87 psi (450 to 600 kPa). Check the outlet pressure of
the trochoid feed pump by removing the plug and
attaching a pressure gauge to the port shown in
. The plug has M12x1.25 threads. You will have
to make an adaptor to attach a pressure gauge. Replace
the trochoid feed pump if the outlet pressure is below
the pressure specifications in the following table.
