2

Figure 3:
Finger tighten Flexplate Pilot Bolt (1) before
inserting remaining Flexplate Retaining Bolts.
Tighten Flexplate Bolts in a star pattern as
numbered 1-6.
Torque Flexplate Retaining Nuts and
Flexplate Pilot Bolt.

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 55 of 117

Front End Accessory Drive (FEAD)
Component Replacement
REMOVAL PROCEDURE
NOTE 1: Depending on configuration, Pulley and Tensioner locations and sizes may be different.
NOTE 2: A bolt-on Pulley used on for the Dual A/C option is tightened using a crosshatch pattern.
NOTE 3: Belt routing diagrams may be found in the OEM service manual.
1. Secure vehicle.
2. Verify engine is off and has had ample
cooling time before attempting
procedure.
3. If necessary; varies by application:
Remove Fan Shroud and/or Fan.
Follow OEM procedure.
4. Using a ½-in drive breaker bar at
position (1) on Tensioner (2), relieve
tension on Main Accessory Drive Belt.
Figures 1 through 6
5. Remove Main Accessory Drive Belt.
6. Remove Retaining Bolt(s) for
component being serviced. NOTE:
Refer to Figure 6 for general pulley
identification.

1

2

Figure 1:
No A/C or Air Brake Compressor
1

INSTALLATION PROCEDURE
1. Install Retaining Bolt(s) for component
being serviced.
2. Tighten Retaining Bolt(s). Refer to
Front End Accessory Drive Torque
Specifications.
3. Route and install Main Accessory Drive
Belt. Follow OEM procedure.
4. If removed: Install Fan and/or Fan
Shroud.

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Figure 2:
No A/C with Air Brake Compressor

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 56 of 117

1
1

1

2

2

Figure 4:
Single A/C with Air Brake Compressor

2

Figure 3:
Single A/C without Air Brake Compressor

6

2
2

1

5

1
6

4

5

7

8

8
7

Figure 5:
Dual A/C without Air Brake Compressor
NOTE: Dual A/C Belt Tensioner (7)
with ½” Drive Socket (8)

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3

Figure 6:
Dual A/C with Air Brake Compressor.
Harmonic Damper (3), Air Brake Compressor Idler
Pulleys (4), Large Idler Pulleys (5),
and Small Idler Pulleys (6)
NOTE: Dual A/C Belt Tensioner (7)
with ½” Drive Socket (8)

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 57 of 117

Front Engine Mount Replacement
FRONT

REMOVAL PROCEDURE
1. Verify vehicle is secured properly.
Ensure engine is off and cool.
2. Support engine using jack stands placed
as indicated on Lower Engine Rail Pads
(1). Figure 1

3.
4.
5.
6.

DO NOT lift or support engine on Oil
Pan (2).
Using jack stands, relieve load on Front
Engine Mount (4). Figures 1 and 2
Remove two (2) Front Engine Mount to
Frame Bolts (not shown) at position (3).
Figures 1 and 2
Remove four (4) Front Engine Mount to
Engine Nuts (5). Figure 2
Remove Front Engine Mount from
vehicle.

4
3

1

2
Figure 1:
Lower Engine Rail Pad jacking points (1),
Front Engine Mount (4), Oil Pan (2),
Front Engine Mount to Frame Bolt locations (3)

INSTALLATION PROCEDURE
1. Install Front Engine Mount (4) using four
(4) Front Engine Mount to Engine Nuts
(5). Figure 2
2. Tighten Front Engine Mount to Engine
Nuts (5). Refer to Engine Mechanical
Torque and Clearance Specifications.
3. Remove jack stands.
When lowering engine, align two
(2) Front Engine Mount bolt holes
(3) with vehicle frame holes.
Figure 2
4. Tighten two (2) Front Engine Mount to
Frame Bolts (not shown). Refer to OEM
specifications.
5. Verify proper operation.

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5
4

Figure 2:
Front Engine Mount (4),
Front Engine Mount Bolt Holes (3),
Front Engine Mount to Engine Nuts (2)

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 58 of 117

Fuel Distribution Block Replacement
REMOVAL PROCEDURE
1. Secure vehicle outside in a safe area.
2. Bleed Fuel Lines. Refer to NFPA 58 for
Fuel Line Bleed Procedure.
3. Bring vehicle into service bay and secure.
4. Remove Upper Intake Manifold. Refer to
Upper Intake Manifold Replacement.
5. Passenger side only: Remove Fuel Return
Line from Fuel Distribution Block (2) at
Nipple (4). Refer to Fuel Supply and Fuel
Return Line Replacement. Figure 1
6. Passenger side only: Remove Engine Fuel
Return Lines (6) at Distribution Block (2).
7. Passenger side only: Remove Fuel ByPass Solenoid (7). Refer to Fuel By-Pass
Solenoid Replacement. Figures 1 & 2
8. Driver side only: Remove Fuel Supply Line
at Fuel Distribution Block (1) Nipple (3).
Refer to Fuel Supply and Fuel Return Line
Replacement. Figure 1
9. Driver side only: Remove Engine Fuel
Supply Lines (5) at Distribution Block (1).
10. Remove four (4) Fuel Distribution Block
Retaining Bolts (11) securing Distribution
Block (1 or 2) to Bracket (9). Figure 2
11. Remove respective Fuel Distribution Block
(1 or 2). Figures 1 and 2

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1

6

3

7

4

2

Figure 1:
Driver side Fuel Distribution Block (1),
Passenger side Fuel Distribution Block (2),
Fuel Supply Line Nipple (3), Fuel Return Line
Nipple (4), Engine Fuel Supply Line Fittings (5),
Engine Fuel Return Line Fittings (6),
Fuel By-Pass Solenoid (7)

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 59 of 117

INSTALLATION PROCEDURE
1. Passenger side only: Install Fuel ByPass Solenoid (7) Refer to Fuel ByPass Solenoid Replacement. Figures
1&2
2. Install respective Fuel Distribution
Block (1 or 2) with four (4) Retaining
Bolts (11). Refer to Fuel System
Torque and Tightening Specifications.
Figure 2
3. Passenger side only: Connect Engine
Fuel Return Line (6) Fittings (10) to
Fuel Distribution Block (2). Refer to
Fuel System Torque and Tightening
Specifications. Figures 1 & 2
4. Passenger side only: Connect Fuel
Return Lines to Fuel Distribution Block
(2) Nipple (4). Refer to Fuel System
Torque and Tightening Specifications.
5. Driver Side only: Connect Engine Fuel
Supply Lines (5) to Fuel Distribution
Block (1). Refer to Fuel System
Torque and Tightening Specifications.
6. Driver Side only: Connect Fuel Supply
Line to Fuel Distribution Block (1)
Nipple (3). Refer to Fuel Supply and
Fuel Return Line Replacement and
Fuel System Torque and Tightening
Specifications. Figure 1
7. Pressurize fuel system to prepare for
leak check as follows:
a. Open Fuel Tank Supply and Return
Valves.
b. Use a Power Probe or similar tool
to apply power to two wires of the
Fuel By-Pass Solenoid (7)
Electrical Connector (a) to
pressurize fuel system. Figure 3
8. Perform leak check. Refer to Fuel
System Leak Detection Procedure.
9. Install Upper Intake Manifold. Refer to
Upper Intake Manifold Replacement.
10. Verify proper operation.

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5
3
1

10

9
11

7

Figure 2:
Passenger side Fuel Distribution Block detail:
Fuel Return Line Nipple (3), Engine Fuel Return Line
Nipples (5), Engine Fuel Return Line Fittings (10),
Fuel Distribution Block Retaining Bolts (11),
Fuel By-Pass Solenoid (7) Electrical Connector (8).
NOTE: It is not necessary to remove Fuel Distribution
Block Bracket (9).

a

7

Figure 3:
Fuel By-Pass Solenoid (7), Electrical Connector (a)

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 60 of 117

Fuel Injector Replacement
REMOVAL PROCEDURE
FRONT

Inspect Fuel Injector O-Rings (7) & (8)
and replace if damaged. Figure 3

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Figure 1:
Fuel Injector Harness Connectors (9)

1

3

Injectors 2-4-6-8 are on passenger
side Fuel Rail; Injectors 1-3-5-7 are
on driver side Fuel Rail.
9. Rotate Fuel Injector (1) to access Snap
Ring (2). Figures 2 & 4
10. Remove Fuel Injector Snap Ring (2)
using snap ring pliers. Figures 2 & 4
11. Remove Fuel Injector (1) from Fuel Rail
(4). Figures 2 & 4
12. Inspect Injector Bore (3) in Fuel Rail for
signs of debris. Figures 2 & 4
13.

9

2

5

FRONT

1. Secure vehicle.
2. Bleed Fuel Lines outside. Refer to
NFPA 58 Fuel Line Bleed Procedure.
3. Bring vehicle into service bay and
secure.
4. Remove Battery Negative (–) Cable.
5. Remove Fuel Supply and Return Lines.
Refer to Fuel Supply and Fuel Return
Line Replacement.
6. Remove Alternator. Refer to Alternator
Removal.
7. Remove Upper Intake Manifold. Refer to
Upper Intake Replacement.
8. Disconnect Fuel Injector Harness
Connectors (9) from Fuel Injector
Electrical Connectors. Figure 1

4

Figure 2:
Fuel Injector (1), Fuel Injector Snap Ring (2),
Fuel Injector Electrical Connector (5)
Fuel Injector Bore (3), Fuel Rail (4)

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 61 of 117

INSTALLATION PROCEDURE
1. Lubricate Fuel Injector O-Rings (7) and
(8) with clean engine oil. Figure 3
2. Install Fuel Injector (1) into Fuel Injector
Bore (3) on Fuel Rail (4). Figures 2 & 4
3. Install Fuel Injector Snap Ring Retainer
(2). Figures 2 & 4
Verify Snap Ring is fully seated;
Snap Ring Gap (6) must be 3 mm
minimum.
4. Verify Fuel Injector Adapter (not shown)
seals properly to Fuel Injector Delivery
Tube Upper O-Ring (not shown). Refer
to Fuel Injector Delivery Tube
Replacement.
5. Connect Fuel Injector Harness
Connectors (9) to Fuel Injector
Electrical Connectors (5). Figures 1, 2,
3, & 4
Apply dielectric grease to
connectors.
6. Install Fuel Supply and Fuel Return
Lines. Refer to Fuel Supply and Fuel
Return Line Replacement.
7. Pressurize fuel system to prepare for
leak check as follows:
a. Open Fuel Tank Supply and Return
Valves. Refer to OEM procedure.
b. Use a Power Probe or similar tool to
apply power to two wires of the Fuel
By-Pass Solenoid (10) Electrical
Connector (11) to pressurize fuel
system. Figure 5
8. Perform leak check. Refer to Fuel
System Leak Verification Procedure.
9. Install Upper Intake Manifold. Refer to
Upper Intake Replacement.
10. Connect negative (–) Battery Cable.
11. Verify proper operation.

5

1

7
8

Figure 3:
Upper Fuel Injector O-Ring (7), Fuel Injector (1),
Fuel Injector Electrical Connector (5),
Lower Fuel Injector O-Ring (8)
4

2

5

6

3

1

Figure 4:
Fuel Rail (4), Fuel Injector Bore (3)
Installed Fuel Injector (1), Electrical Connector (5),
3 mm Minimum Gap (6) for Fuel Injector Snap Ring (2)
10

11

Figure 5:
Fuel By-Pass Solenoid (10), Electrical Connector (11)

DSM.0052 Ver. 1.0 05/27/2022

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 62 of 117

Fuel Injector Tube Replacement
Fuel Line pressure can exceed 250 psi (17 bar). Exercise caution when removing Fuel Lines
and Fuel Rails.
REMOVAL PROCEDURE
1. Secure vehicle outdoors in a safe location.
2. Bleed Fuel Lines. Refer to NFPA 58 Fuel
Line Bleed Procedure.
3. Bring vehicle into service bay and secure.
4. Remove Upper Intake Manifold. Refer to
Upper Intake Manifold Replacement.
5. Remove the respective Fuel Rail for Fuel
Injector Tube (3) being replaced. Refer to
Fuel Rail Replacement. Figures 1 & 2
6. Remove Injector Tube Retaining Snap
Ring (2). Figure 3
7. Remove Fuel Injector Tube (3). Figures 1,
2, 3, & 4
8. Inspect Fuel Injector Tube (3) for damage.
9. Inspect Fuel Injector Tube O-Rings (3) and
(7) for damage; replace as necessary.
Figures 3 & 4
10.

3
Figure 1:
Driver side Fuel Rail
with Fuel Injector Tubes (3)

Inspect Fuel Rail Injector Tube
Opening for debris; clean as
necessary.

3
Figure 2:
Passenger side Fuel Rail with
Fuel Injector Tubes (3)

DSM.0052 Ver. 1.0 05/27/2022

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 63 of 117

INSTALLATION PROCEDURE

4

1. Apply a light film of Parker O-Lube or
equivalent to Fuel Injector Tube ORings (4) and (7). Figure 4
2. Install Fuel Injector Tube O-Ring (7)
into Fuel Rail. Figures 3 & 4
3. Install Fuel Injector Tube (3) in position
in Fuel Rail. Figure 3
4. Install Fuel Injector Tube Retaining
Snap Ring (2).

5.
6.

7.
8.
9.