Precautions; Troubleshooting - Toyota 4-Runner 1985 Repair Manual

FU-2
Problem
Engine will not start/
Hard to start
(cranks ok)
Rough idle or stalls
Engine hesitates/
Poor acceleration
Engine dieseling
(runs after ignition
switch is turned off)
Poor gasoline
mileage
Insufficient fuel
supply to
carburetor
FUEL SYSTEM - Precautions, Troubleshooting
PRECAUTIONS
1. Before working on the fuel system, disconnect the cat
from the negative battery terminal.
2. When working on the fuel system, keep away from possi-
ble fire hazards and do not smoke.
3. Keep gasoline off rubber or leather parts.
4. Work on only one component group at a time to avoid con-
fusion between similar looking parts.
5. Keep work area clean to avoid contamination of the car-
buretor and com ponents.
6. Be careful not to mix up or lose clips or springs.
TROUBLESHOOTING
Possible cause Remedy Page
Carburetor problems Repair as necessary
FU-4
• Choke operating
• Flooding
• Needle valve sticking or clogged
• Vacuum hose disconnected or
damaged
• Fuel cut solenoid valve not open
Carburetor problems Perform on-vehicle inspection
FU-3
• Idle speed incorrect
of carburetor
• Slow jet clogged
• Idle mixture incorrect
• Fuel cut solenoid valve not open
• Fast idle speed setting incorrect
(cold engine)
• Choke system faulty
• Secondary throttle valve not
closed
Fuel line clogged Check fuel line
Carburetor problems Repair as necessary
FU-4
• Float level too low
• Accelerator pump faulty
• Power valve faulty
• Choke valve closed (hot engine)
• Choke system
Carburetor problems Repair as necessary
FU-4
• Linkage sticking
• Idle speed or fast
idle speed out of adjustment
• Fuel cut solenoid faulty
Fuel leak Repair as necessary
Carburetor problems Perform on-vehicle inspection
FU-3
• Choke faulty
of carburetor
• Idle speed too high
• Deceleration fuel cut system
faulty
• Power valve always open
Fuel filter clogged Replace fuel filter
Fuel pump faulty Replace fuel pump
FU-28
Fuel line clogged Check fuel line
FU-30
Fuel line bent or kinked Replace fuel line