Carburetor - Icing in Cold Weather Operation

BULLETIN NUMBER ISSUE DATE GROUP
SB86-03-002 December 5, 1986 EMISSIONS
CARBURETOR ICING (G200 ENGINE)

Heated Air Intake System:

VEHICLES AFFECTED

P'UP (KB) and Trooper II (KT) Federal models with G200 engine.

SERVICE INFORMATION

In extremely cold weather operation, carburetor icing may occur. In some cases, the use of substandard
replacement air cleaner elements has allowed foreign matter to enter the air cleaner housing and contaminate the thermosensor. Make sure that a genuine Isuzu air cleaner element or certified replacement is used.

If the problem persists, a field fix kit is available which, modifies the operation of the heated air intake system. Figure 1 is a schematic of the system showing the changes made by this kit.

Thermosensor:

SERVICE PROCEDURE

1. Remove the air cleaner assembly as described in the appropriate Workshop Manual.

2. Replace the thermosensor inside the air cleaner assembly with the new thermosensor from the kit.
Install the existing vacuum hoses to the new thermosensor (Figure 2).

Vacuum Hose:

3. Remove and discard the vacuum hose which connects the intake manifold port to the thermosensor tee fitting (Figure 3).

Vacuum Reservoir Tank:

4.If the kit is being installed on a Trooper II, the new vacuum hoses must be shortened. Shorten the redstripe hose by 3-1/2 inches; shorten the white-stripe hose by 7 inches.
5.Connect the kit's vacuum hoses to the new vacuum reservoir tank. The red-stripe hose connects to the port marked "0". The white-stripe hose connects to the port marked "10". See Figure 4.

Hole Placement:

6. Drill two holes (3/16 in. diameter) in the left-hand engine compartment wall. See Figure 5 for hole placement on P'UP models; see Figure 6 for hole placement on Trooper II models.
7. Screw the vacuum reservoir tank to the engine compartment wall using the 2 self-tapping screws provided in the kit.

Vacuum Hoses:

8. Connect the red-stripe vacuum hose to the intake manifold port. Connect the white-stripe hose to the thermosensor tee fitting. Route the hoses as shown in Figure 7 (P'UP) or Figure 8 (Trooper II); use the 3 bands provided in the kit to secure the hoses to existing equipment.
9. Install the air cleaner assembly.

10. Place the new hose routing label over the original label (on the underside of the hood).
PARTS INFORMATION

Part No. Description

8-94439-108-0 Field Fix Kit

This kit consists of the following pans:

Description Quantity

Thermosensor kit 1
Vacuum reservoir tank 1
Self-tapping screw 2
Rubber hose (red stripe) 1 (length 39 inches)
Rubber hose (white stripe) 1 (length 38 inches)
Band clip 3
Hose routing label 1

FLAT RATE MANUAL UPDATE

OPER.
OPERATION TASK SPEC. P'UP TROOPER
NUMBER INSTR. TROOPER II

030499 G200 CARBURETOR ICING Install .5 .5
FIELD FIX KIT