Usage:
Crankshaft Turns
Engine Will Not Start
Engine Will Not Start
Step 1
Install the Electronic Control Analyzer and Programmer (ECAP) or the Digital Diagnostic Service Tool (DDT). See Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR3913.
Step 2
Electronic Self Check. Check the electronics diagnostic lamp on the dash to determine if there are any faults in the engine electronics system. Repair or replace parts as needed. Refer to Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR3913.
Step 3
Check Cranking Speed Of Crankshaft. Using the ECAP or DDT, check the speed of the crankshaft while the starter is cranking. If the crankshaft speed is below 250 rpm, then proceed to item 4. If the crankshaft speed is above 250 rpm, then proceed to item 5.
Step 4
Possible Causes Of Low Cranking Speed:
1. Low Battery Voltage
Check battery voltage. If the voltage is less than 8 volts for a 12 volt system, or 16 volts for a 24 volt system, put a charge to the battery. If the battery will not hold a charge, load test the battery. Use the 6V4930 Battery Load Tester and make reference to Special Instruction, Form No. SEHS8268 for complete information on use of the 6V4930 Battery Load Tester.
2. Defective Cable, Battery To Starter, Or Defective Connection
With ignition switch in the START position, check the voltage at the connection of the battery cable to the starter. If there is no voltage, or if the voltage is low at this connection and there is good voltage at the battery, check for a defective cable or connection between the battery and the starter.
3. Oil Too Thick For Free Crankshaft Rotation
Refer to the 3176 Truck Engine Operation And Maintenance Manual, Form No. SEBU6163 for the correct SAE grade oils for the ambient temperatures at which the engine is being operated. At temperatures below -23° C (-10° F), it may be necessary to warm the oil for free crankshaft rotation.
4. Defective Starter Motor
Remove and test. Make repairs as necessary or install a new starter motor.
5. Extra Outside Loads.
Damage to the power take-off equipment (if so equipped) and/or transmission can put extra load on the engine and prevent free rotation of the crankshaft. To check, disconnect the transmission and power takeoff, and start the engine.
6. Transmission Or Power Take-off Problem
See the Truck Manufacturer's Service Manual.
7. Internal Engine Problem
Disassemble the engine and check all components for damage. See 3176 Diesel Truck Engine Disassembly And Assembly, Form No. SENR3914.
Step 5
Can Exhaust Smoke Be Seen While Starting?
If exhaust smoke can be seen while starting the engine, then proceed to item 6. If exhaust cannot be seen while starting the engine, then proceed to item 7.
Step 6
A. Possible Causes-Engine Will Not Start
Cold Outside Temperatures
It may be necessary to use starting aids, or to heat engine oil or coolant at temperatures below 0° C (32° F).
B. Air In Fuel System
With air in the fuel system, the engine will normally be difficult to start, run rough, and release a large amount of white smoke. If the engine will not start, loosen the highest drain plug on the front end of the fuel manifold. Operate the fuel priming pump until the flow of fuel from the loosened drain plug is free of air. Tighten the drain plug. If the air cannot be removed in this way, put 35 kPa (5 psi) of air pressure to the fuel tank.
| NOTICE |
|---|
Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result. |
Check for leaks at the connections between the fuel tank and the fuel transfer pump. If leaks are found, tighten the connections or replace the lines. If there are no visual leaks, remove the fuel supply line from the tank and connect it to an outside fuel supply. If this corrects the problem, the suction line (standpipe) inside the fuel tank has a leak.
C. Poor Quality Fuel
Remove a small amount of fuel from the tank and check for water or other contamination in the fuel. See Special Instruction, Form No. SEHS7067 for complete information on fuel recommendations for Caterpillar diesel engines. If there is water in the fuel, remove the fuel until it is free of water. Fill with good quality fuel. Change the fuel filter and prime the system using the fuel priming pump. If there is water in the fuel, use an outside source of good quality fuel, prime and start the engine. If the engine starts easily, remove all the fuel from the fuel tank and fill with good quality fuel. Prime the fuel system if necessary.
D. Low Fuel Pressure
Change the fuel filter. If the pressure remains low, check the by-pass valve in the fuel transfer pump and the fuel pressure regulating valve in the fuel manifold adapter. Debris in the system can cause the valves to remain in the open position.
E. Fuel Injection Timing Out Of Calibration
Check the fuel injection timing calibration and make necessary adjustments. See the topics, Engine Test Procedure Number P-402, [Checking Electronic Injection Timing With The Timing Adapter Tool Group And The ECAP (Electronic Control Analyzer and Programmer)], and Engine Test Procedure Number P-403, [Calibrating Electronic Injection Timing With The Timing Adapter Tool Group And The ECAP (Electronic Control Analyzer and Programmer)], in Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR3913.
F. Valve Adjustment Not Correct
Check and make necessary adjustments. See the topic, Valve Clearance Setting, in 3176 Diesel Truck Engine Systems Operation And Testing and Adjusting, Form No. SENR3909. Intake valve clearance is 0.38 mm (.015 in), and exhaust valve clearance is 0.64 mm (.025 in). Also check for bent or broken push rod or other valve train parts.
G. Defective Unit Injector(s)
Find a defective unit injector by running the engine at the rpm where it runs rough. Use the Electronic Control Analyzer and Programmer (ECAP) service tool single cylinder cutout procedure (see Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR3913) to stop the fuel supply to each cylinder. If a cylinder is found where the cutout makes no difference on the rough running, drain the fuel supply manifold and remove that unit injector and test it.
Testing of the injectors must be done off of the engine. Use the 1U6661 Pop (Injector) Tester Group with a 1U6663 Injector Holding Block, and a 1U6665 Power Supply, to test the injectors. For the test procedure refer to Special Instruction, Form No. SEHS8867, Using The 1U6661 Pop (Injector) Tester. For test specifications refer to Special Instruction, Form No. SEHS8804, Unit Injector Test Specifications for 1.7 Liter Engines.
NOTE: Inspect and repair as necessary the sealing surface (seat) of the injector sleeve in the cylinder head when removing and installing an injector. The injector sealing surface (seat) must be free of scratches or evidence of combustion products. If it is necessary to rework (ream) or replace the sleeve use 4C4054 Tool Group and refer to Special Instruction, Form No. SEHS9120, Removal And Installation Of Unit Injector Sleeve.
If two adjacent cylinders are misfiring and the unit injectors test good, then there most likely is a cylinder head gasket leak between the two cylinders. See 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914 for correct replacement of the cylinder head gasket.
H. Low Compression
See the topic, Misfiring and Running Rough.
Step 7
7. Possible Causes-Engine Will Not Start
A. No Fuel In Tank(s)
Visually check fuel level in the tank(s). Be sure the tank selection valve is open for the tank with fuel in it. Be sure the fuel line between the tanks (if more than one) is open.
B. No Fuel From Unit Injectors
1. Prime the fuel system per item 6B.
2. If temperatures are below -12° C (10° F), a poor quality fuel can "wax" and cause a restriction in the system. Install a new fuel filter. It may be necessary to drain the entire fuel system and replace with No. 1 grade fuel, or a blend of fuel depending on the air temperature.
3. Check for a fuel supply line restriction by removing the fuel supply line from the fuel filter base. Put 35 kPa (5 psi) of air pressure to the fuel tank.
| NOTICE |
|---|
Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result. |
If there is no flow or a weak flow of fuel from the supply line, clean or replace plugged lines.
4. Check fuel transfer pump pumping gears and drive gear on the camshaft. Repair or replace as necessary. See 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914.
5. Drain the fuel manifold, remove each unit injector (see 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914) and bench test unit injectors to check flow. Replace plugged unit injectors.
Testing of the injectors must be done off of the engine. Use the 1U6661 Pop (Injector) Tester Group with a 1U6663 Injector Holding Block, and a 1U6665 Power Supply, to test the injectors. For the test procedure refer to Special Instruction, Form No. SEHS8867, Using The 1U6661 Pop (Injector) Tester. For test specifications refer to Special Instruction, Form No. SEHS8804, Unit Injector Test Specifications for 1.7 Liter Engines.
NOTE: Inspect and repair as necessary the sealing surface (seat) of the injector sleeve in the cylinder head when removing and installing an injector. The injector sealing surface (seat) must be free of scratches or evidence of combustion products. If it is necessary to rework (ream) or replace the sleeve use 4C4054 Tool Group and refer to Special Instruction, Form No. SEHS9120, Removal And Installation Of Unit Injector Sleeve.
C. Restriction In Exhaust System
Loosen the exhaust pipe from the exhaust manifold and start engine. If the engine starts easily, check the exhaust system for damage and/or restrictions.
D. Electrical Problem Ahead Of Electronic Control Module (ECM)
Check for a problem with the electrical supply to the ECM.
Crankshaft Does Not Turn
Step 8
Possible Causes-Engine Will Not Start
A. No Battery Voltage
Check battery voltage. If there is no battery voltage, put a charge to the battery. If battery will not hold a charge, load test the battery. Use the 6V4930 Battery Load Tester and make reference to Special Instruction, Form No. SEHS8268 for complete information on use of the 6V4930 Battery Load Tester.
B. Defective Switch, Defective Wiring Or Connection In Switch Circuit
With the ignition switch in the "start" position, check the voltage at the switch connection on the starter solenoid. If there is no voltage, or if the voltage is low at this connection, check the wiring, connections, ignition switch, and magnetic switch (if used).
C. Defective Cable, Battery To Starter, Or Defective Connection
With the ignition switch in the "start" position, check the voltage at the connection of the battery cable to the starter. If there is no voltage, or if the voltage is low at this connection and there is good voltage at the battery, check for defective cable or connection between the battery and the starter.
D. Defective Starter Solenoid
Remove and repair a solenoid which does not work when the voltage is correct at both the battery and switch connections on the starter solenoid.
E. Defective Starter Motor
If the solenoid works, but the starter motor does not turn the crankshaft, the starter motor is defective. Remove the starter motor (see 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914), and try to turn the crankshaft by hand (to be sure a mechanical failure inside the engine, transmission, or power take-off is not preventing the crankshaft from turning). If the crankshaft turns freely by hand, install the starter motor and engage the starter motor again. If the starter motor still will not turn the crankshaft, remove the starter motor. Repair the starter motor, or install a new one.
F. Transmission Or Power Take-Off Problem
If the crankshaft cannot be turned by hand, disconnect the transmission and power take-off (if so equipped). If the crankshaft will now turn, find the cause of the problem in the transmission or power take-off and make necessary corrections.
G. Hydraulic Cylinder Lock
Drain the fuel supply manifold, remove each unit injector (see 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914), and check for fluid in the cylinders while turning the crankshaft. If fluid is found in the cylinders, it must be removed (to prevent hydraulic cylinder lock) prior to reinstalling the unit injectors. Check each unit injector before reinstalling.
Testing of the injectors must be done off of the engine. Use the 1U6661 Pop (Injector) Tester Group with a 1U6663 Injector Holding Block, and a 1U6665 Power Supply, to test the injectors. For the test procedure refer to Special Instruction, Form No. SEHS8867, Using The 1U6661 Pop (Injector) Tester. For test specifications refer to Special Instruction, Form No. SEHS8804, Unit Injector Test Specifications for 1.7 Liter Engines.
NOTE: Inspect and repair as necessary the sealing surface (seat) of the injector sleeve in the cylinder head when removing and installing an injector. The injector sealing surface (seat) must be free of scratches or evidence of combustion products. If it is necessary to rework (ream) or replace the sleeve use 4C4054 Tool Group and refer to Special Instruction, Form No. SEHS9120, Removal And Installation Of Unit Injector Sleeve.
H. Defective Ring Gear
If the starter is working properly, but the crankshaft still does not turn, some of the teeth on the ring gear may be missing. Inspect the ring gear and replace if needed (see 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914).
I. Internal Engine Problem
If each of the above items have been checked and are not the problem, the engine must be disassembled (see 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914) to check for internal problems. Some of these internal problems may be bearing seizure, piston seizure, or valves making contact with pistons.