3306 DIRECT INJECTION VEHICULAR ENGINE WITH NEW SCROLL FUEL – Testing and Adjusting

Troubleshooting

Troubleshooting can be difficult. The Troubleshooting Index gives a list of possible problems. To make a repair to a problem, make reference to the cause and correction on the pages that follow.

This list of problems, causes and corrections will only give an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendation in the list.

Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list is only a guide and cannot give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.

Troubleshooting Index

1. Engine Will Not Turn When Start Switch Is On.
2. Engine Will Not Start.
3. Misfiring Or Running Rough.
4. Stall At Low rpm.
5. Sudden Changes In Engine rpm.
6. Not Enough Power.
7. Too Much Vibration.
8. Loud Combustion Noise.
9. Loud Noise (Clicking) From Valve Compartment.
10. Oil In Cooling System.
11. Mechanical Noise (Knock) In Engine.
12. Fuel Consumption Too High.
13. Loud Noise From Valves Or Valve Operating Components.
14. Little Movement Of Rocker Arm And Too Much Valve Clearance.
15. Valve Rotocoil Or Spring Lock Is Free.
16. Oil At The Exhaust.
17. Little Or No Valve Clearance.
18. Engine Has Early Wear.
19. Coolant In Lubrication Oil.
20. Too Much Black Or Gray Smoke.
21. Too Much White Or Blue Smoke.
22. Engine Has Low Oil Pressure.
23. Engine Uses Too Much Lubrication Oil.
24. Engine Coolant Is Too Hot.
25. Exhaust Temperature Is Too High.
26. Starter Motor Does Not Turn.
27. Alternator Gives No Charge.
28. Alternator Charge Rate Is Low Or Not Regular.
29. Alternator Charge Is Too High.
30. Alternator Has Noise.

Problem 1: Engine Crankshaft Will Not Turn When Start Switch Is On

Probable Cause:

1. Battery Has Low Output:

Make Reference to Problem 27.

2. Wires Or Switches Have Defect:

Make Reference to Problem 27.

3. Starter Motor Solenoid Has A Defect:

Make Reference to Problem 26.

4. Starter Motor Has A Defect:

Make Reference to Problem 26.

5. Inside Problem Prevents Engine Crankshaft From Turning:

If the crankshaft cannot be turned after the drive equipment is disconnected, remove the fuel nozzles and check for fluid in the cylinders while the crankshaft is turned. If fluid in the cylinders is not the problem, the engine must be disassembled to check for other inside problems. Some of these inside problems are bearing seizure, piston seizure, wrong pistons installed in the engine, and valves making contact with pistons.

Problem 2: Engine Will Not Start

Probable Cause:

1. Slow Cranking Speed:

Make reference to Problem 27.

2. No Fuel In The Housing For The Fuel Injection Pumps:

Fill the housing for the fuel injection pumps with fuel with the priming pump. Remove the air with the bleed valve.

3. Dirty Fuel Filter:

Install new fuel filter.

4. Dirty Or Broken Fuel Lines:

Clean or install new fuel lines as necessary.

5. No Fuel To Cylinders:

Put fuel in fuel tank. “Prime” (remove the air and/or low quality fuel from the fuel system).

6. Bad Quality Fuel:

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank.

7. Fuel Has “Cloud Point” Higher Than Atmospheric Temperature (“Cloud Point” = Temperature Which Makes Wax Form In Fuel):

Drain the fuel tank lines, and fuel injection pump housing. Change the fuel filter. Fill the tank with fuel which has the correct “cloud point” and remove the air from the system with the priming pump.

8. Wrong Fuel Injection Timing:

Make adjustment to timing.

9. Over Fueling Spring Not Installed:

Install over fueling spring.

10. Fuel Ratio Control Has A Defect:

Check fuel ratio control setting. Adjust if necessary.

Problem 3: Misfiring Or Running Rough

Probable Cause:

1. Air In The Fuel System:

Find air leak in the fuel system and correct. Remove air from fuel system. See Fuel System in Testing and Adjusting.

2. Fuel Pressure Is Low:

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure at the fuel injection pump housing. If fuel pressure at high idle is lower than 105 kPa (15 psi), install a new filter element. If fuel pressure is still low, check the pumping spring and the check valves in the fuel transfer pump.

3. Leak Or Break In Fuel Line Between Injection Pump And Injection Valve:

Install a new fuel line.

4. Defect In Fuel Injection Valve(s) Or Injection Pump(s):

Run engine at rpm that gives maximum misfiring or rough running. Then loosen a fuel line nut on the injection valve for each cylinder, one at a time. Find the cylinder where loosening the fuel line nut does not change the way the engine runs. Test the injection pump and injection valve for that cylinder. Install new parts where needed.

5. Fuel System Not Timed Correctly To Engine:

Make adjustment to timing if necessary.

6. Wrong Valve Clearance:

Make adjustment, See the Subject Valve Clearance in Testing and Adjusting.

7. Bent Or Broken Push Rod:

Replacement of push rod is necessary.

8. Worn Valve Seat Or Face Of Valve:

Reconditioning of cylinder head is needed.

Problem 4: Stall At Low RPM

Probable Cause:

1. Idle RPM Too Low:

Make adjustments to governor so idle rpm is the same as given in the Fuel Setting And Related Information Fiche.

2. Defect In Fuel Injection Valve(s) Or Fuel Injection Pump(s):

Run engine at rpm that gives maximum misfiring or rough running. Then loosen a fuel line nut on the injection pump for each cylinder, one at a time. Find the cylinder where loosening the fuel line nut does not change the way the engine runs. Test the injection pump and injection valve for that cylinder. Install new parts where needed.

Problem 5: Sudden Changes In Engine Speed (rpm)

Probable Cause:

1. Failure Of Governor Or Fuel Injection Pump:

Look for damaged or broken springs, linkage or other parts. Remove the governor. Check for free travel of the fuel rack. Be sure fuel injection pumps are installed correctly. Check for correct governor spring. Install new parts for those that have damage or defects.

Problem 6: Not Enough Power

Probable Cause:

1. Air In The Fuel System:

Find air leak in the fuel system and correct. Remove air from fuel system. See FUEL SYSTEM in Testing and Adjusting.

2. Fuel Pressure Is Low:

Make sure there is fuel in the fuel tank. Look for leaks, or bad bends, in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure at high idle is lower than 105 kPa (15 psi), install a new fuel filter element. If fuel pressure is still low, check the pumping spring and the check valves in the fuel transfer pump.

3. Bad Quality Fuel:

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank.

4. Constant Bleed Valve Stays Open Or Closed:

Install new parts if needed.

5. Leaks In Air Inlet System:

Check the pressure in the air inlet manifold. Look for restrictions in the air cleaner.

6. Governor Linkage:

Make adjustment to get full travel of linkage. Install new parts for those that have damage or defects.

7. Wrong Valve Clearance:

Make adjustment, See the Subject Valve Clearance in Testing and Adjusting

8. Defect In Fuel Injection Valve(s) Or Fuel Injection Pump(s):

Run engine at rpm that gives maximum misfiring or rough running. Then loosen a fuel line nut on the injection pump for each cylinder, one at a time. Find the cylinder where loosening the fuel line nut does not change the way the engine runs. Test the injection pump and injection valve for that cylinder. Install new parts where needed.

9. Wrong Fuel Injection Timing:

Make adjustment to timing.

10. Fuel Setting Too Low:

Make reference to the Fuel Setting And Related Information Fiche.

11. Turbocharger Has Carbon Deposits Or Other Causes Of Friction:

Make inspection and repair of turbocharger as necessary.

12. Fuel Ratio Control Has A Defect:

Check fuel ratio control setting. Adjust if necessary. Check diaphragm in fuel ratio control.

Problem 7: Too Much Vibration

Probable Cause:

1. Loose Bolt Or Nut Holding Pulley Or Damper:

Tighten bolt or nut.

2. Pulley Or Damper Has A Defect:

Install a new pulley or damper.

3. Fan Blade Not In Balance:

Loosen or remove fan belts and operate engine for a short time at the rpm that the vibration was present. If vibration is not still present, make a replacement of the fan assembly.

4. Engine Supports Are Loose, Worn, Or Have A Defect:

Tighten all mounting bolts. Install new components if necessary.

5. Misfiring Or Running Rough:

Make reference to Problem 3:

Problem 8: Loud Combustion Noise (Knock)

Probable Cause:

1. Bad Quality Fuel:

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank.

2. Defect In Fuel Injection Valve(s) Or Fuel Injection Pump(s):

Run engine at rpm that gives maximum combustion noise. Then loosen a fuel line nut on the injection pump for each cylinder, one at a time. Find the cylinder where loosening the fuel line nut stops the combustion noise. Test the injection pump and injection valve for that cylinder. Install new parts where needed.

3. Wrong Fuel Injection Timing:

Make adjustment to timing.

Problem 9: Loud Noise (Clicking) From Valve Compartment

Probable Cause:

1. Damage To Valve Spring(s) Or Locks:

Install new parts where necessary. Locks with defects can cause the valve to slide into the cylinder. This will cause much damage.

2. Not Enough Lubrication:

Check lubrication in valve compartment. There must be a strong flow of oil at engine high rpm, but only a small flow of oil at low rpm. Oil passages must be clean, especially those sending oil to the cylinder head.

3. Too Much Valve Clearance:

Make adjustment. See the Subject Valve Clearance in Testing and Adjusting.

4. Damage To Valves:

Make a replacement of the valve(s) and make an adjustment as necessary.

Problem 10: Oil In Cooling System

Probable Cause:

1. Defect In Core Of Oil Cooler:

Install a new core in the oil cooler.

2. Defect In Head Gasket:

Install a new head gasket.

Problem 11: Mechanical Noise (Knock) In Engine

Probable Cause:

1. Failure Of Bearing For Connecting Rod:

Inspect the bearing for the connecting rod and the bearing surface on the crankshaft. Install new parts when necessary.

2. Damage To Timing Gears:

Install new parts where necessary.

3. Damage To Crankshaft:

Make replacement of the crankshaft.

Problem 12: Fuel Consumption Too High

Probable Cause:

1. Fuel System Leaks:

Large changes in fuel consumption may be the result. Inspect the fuel system for leaks and make repairs as necessary.

2. Fuel And Combustion Noise (Knock):

Small increases in fuel consumption may be the result of fuel nozzles with defects, rough running, or factors causing loss of power. See Problem 3 and Problem 6:

3. Wrong Fuel Injection Timing:

Make an adjustment to fuel injection timing.

Problem 13: Loud Noise From Valves Or Valve Drive Components

Probable Cause:

1. Damage To Valve Spring(s):

Make replacement of parts with damage.

2. Damage To Camshaft:

Make replacement of parts with damage. Clean engine thoroughly.

3. Damage To Valve Lifter:

Clean engine thoroughly. Make a replacement of the camshaft and valve lifters. Look for valves that do not move freely. Make an adjustment to valve clearance. See the Subject Valve Clearance in Testing and Adjusting.

4. Damage To Valve(s):

Make a replacement of the valve(s) and make an adjustment as necessary.

Problem 14: Little Movement Of Rocker Arm And Too Much Valve Clearance

Probable Cause:

1. Too Much Valve Clearance:

Make adjustment. See the Subject Valve Clearance in Testing and Adjusting.

2. Not Enough Lubrication:

Check lubricant in valve compartment. There must be a strong flow of oil at engine high rpm, but only a small flow at low rpm. Oil passages must be clean, especially those sending oil to the cylinder head.

3. Rocker Arm Worn At Face That Makes Contact With Valve:

If there is too much wear, install new rocker arms. Make adjustment of valve clearance, see the Subject Valve Clearance in Testing and Adjusting.

4. End Of Valve Stem Worn:

If there is too much wear, install new valves. Make adjustment of valve clearance, see the Subject Valve Clearance in Testing and Adjusting.

5. Worn Push Rods:

If there is too much wear, install new push rods. Make adjustment of valve clearance, see the Subject Valve Clearance in Testing and Adjusting.

6. Valve Lifters Worn:

If there is too much wear, install new valve lifters. Make adjustment of valve clearance, see the Subject Valve Clearance in Testing and Adjusting.

7. Damage To Valve Lifters:

Install new valve lifters. Check camshaft for wear. Check for free movement of valves or bent valve stem. Clean engine thoroughly. Make adjustment of valve clearance, see the Subject Valve Clearance in Testing and Adjusting.

8. Worn Cams On Camshaft:

Check valve clearance. Check for free movement of valves or bent valve stems. Check for valve lifter wear. Install a new camshaft. Make adjustment of valve clearance, see the Subject Valve Clearance in Testing and Adjusting.

Problem 15: Valve Rotocoil Or Spring Lock Is Free

Probable Cause:

1. Damage To Locks:

Locks with damage can cause the valve to fall into the cylinder. This will cause much damage.

2. Damage To Valve Spring(s):

Install new valve spring(s).

Problem 16: Oil At The Exhaust

Probable Cause:

1. Too Much Oil In The Valve Compartment:

Look at both ends of the rocker arm shaft. Be sure that there is a plug in each end.

2. Worn Valve Guides:

Reconditioning of the cylinder head is needed.

3. Worn Piston Rings:

Inspect and install new parts as needed.

4. Running Engine Too Long At Low Idle:

Don’t let the engine run for long periods of time at low idle.

Problem 17: Little Or No Valve Clearance

Probable Cause:

1. Worn Valve Seat Or Face Of Valve:

Reconditioning of cylinder head is needed. Make adjustment of valve clearance. See the Subject Valve Clearance in Testing and Adjusting.

Problem 18: Engine Has Early Wear

Probable Cause:

1. Dirt In Lubrication Oil:

Remove dirty lubrication oil. Install a new oil filter element. Put clean oil in the engine.

2. Air Inlet Leaks:

Inspect all gaskets and connections. Make repairs if leaks are present.

3. Fuel Leakage Into Lubrication Oil:

This will cause high fuel consumption and low engine oil pressure. Make repairs if leaks are present. Install new parts where needed.

Problem 19: Coolant In Lubrication Oil

Probable Cause:

1. Failure Of Oil Cooler Core:

Install a new core for the oil cooler.

2. Failure Of Cylinder Head Gasket:

Install a new cylinder head gasket. Tighten the bolts holding the cylinder head, according to Specifications.

3. Crack Or Defect In Cylinder Head:

Install a new cylinder head.

4. Crack Or Defect In Cylinder Block:

Install a new cylinder block.

5. Failure Of Seals For Cylinder Liners:

Make a replacement of the seals.

Problem 20: Too Much Black Or Gray Smoke

Probable Cause:

1. Not Enough Air For Combustion:

Check air cleaner for restrictions. Check inlet manifold pressure. Inspect turbocharger for correct operation.

2. Bad Fuel Injection Nozzle(s):

Test all nozzles. Install new nozzles if test shows replacement is needed.

3. Wrong Fuel Injection Timing:

Make adjustment to timing.

Problem 21: Too Much White Or Blue Smoke

Probable Cause:

1. Too Much Lubrication Oil In Engine:

Remove extra oil. Find where extra oil comes from. Put correct amount of oil in engine. Do not put too much oil in engine.

2. Misfiring Or Running Rough:

Make Reference to Problem 3:

3. Wrong Fuel Injection Timing:

Make adjustment to timing.

4. Worn Valve Guides:

Reconditioning of cylinder head is needed.

5. Worn Piston Rings:

Install new piston rings.

6. Failure Of Turbocharger Oil Seal:

Check inlet manifold for oil and make repair to turbocharger if necessary.

Problem 22: Engine Has Low Oil Pressure

Probable Cause:

1. Defect In Oil Pressure Gauge:

Install new gauge.

2. Dirty Oil Filter Or Oil Cooler:

Check the operation of bypass valve for the filter. Install new oil filter elements if needed. Clean or install new oil cooler core. Remove dirty oil from engine. Put clean oil in engine.

3. Diesel Fuel In Lubrication Oil:

Find the place where diesel fuel gets into the lubrication oil. Make repairs as needed. Remove the lubrication oil that has diesel fuel in it. Install a new oil filter element. Put clean oil in the engine.

4. Too Much Clearance Between Rocker Arm Shaft And Rocker Arms:

Check lubrication in valve compartment. Install new parts as necessary.

5. Oil Pump Suction Pipe Has A Defect:

Replacement of pipe is needed.

6. Relief Valve For Oil Pump Does Not Operate Correctly:

Clean valve and housing. Install new parts as necessary.

7. Oil Pump Has A Defect:

Make repair or replacement of oil pump if necessary.

8. Too Much Clearance Between Camshaft And Camshaft Bearings:

Install new camshaft and camshaft bearings if necessary.

9. Too Much Clearance Between Crankshaft And Crankshaft Bearings:

Check the oil filter for correct operation. Install new parts if necessary.

10. Too Much Bearing Clearance For Idler Gear:

Inspect bearings and make replacement as necessary.

11. Orifices For Piston Cooling Not Installed:

Install piston cooling orifices.

Problem 23: Engine Uses Too Much Lubrication Oil

Probable Cause:

1. Too Much Lubrication Oil In Engine:

Remove extra oil. Find where extra oil comes from. Put correct amount of oil in engine. Do not put too much oil in engine.

2. Oil Leaks:

Find all oil leaks. Make repairs as needed.

3. Oil Temperature Is Too High:

Check operation of oil cooler. Install new parts if necessary. Clean the core of the oil cooler.

4. Too Much Oil In Valve Compartment:

Make reference to Problem 16.

5. Worn Valve Guides:

Make reference to Problem 16.

6. Worn Piston Rings And Cylinder Liners:

Install new parts if necessary.

7. Failure of Seal Rings In Turbocharger:

Check inlet manifold for oil and make repair to turbocharger if necessary.

Problem 24: Engine Coolant Is Too Hot

Probable Cause:

1. Restriction To Air Flow Through Radiator Or Restriction To Flow Of Coolant Through The Radiator:

Remove all restrictions to flow.

2. Not Enough Coolant In System:

Add coolant to cooling system.

3. Pressure Cap Has A Defect:

Check operation of pressure cap. Install a new pressure cap if necessary.

4. Combustion Gases In Coolant:

Find out where gases get into the cooling system. Make repairs as needed.

5. Water Temperature Regulator (Thermostat) Or Temperature Gauge Has A Defect:

Check water temperature regulator for correct operation. Check temperature gauge operation. Install new parts as necessary.

6. Water Pump Has A Defect:

Make repairs to the water pump as necessary.

7. Too Much Load On The System:

Make a reduction in the load.

8. Wrong Fuel Injection Timing:

Make adjustment to timing.

Problem 25: Exhaust Temperature Is Too High

Probable Cause:

1. Air Inlet Or Exhaust System Has A Restriction:

Remove restriction.

2. Wrong Fuel Injection Timing:

Make an adjustment to the timing.

Problem 26: Starter Motor Does Not Turn

Probable Cause:

1. Battery Has Low Output:

Check condition of battery. Charge battery or make replacement as necessary.

2. Wires Or Switch Has Defect:

Make repairs or replacement as necessary.

3. Starter Motor Solenoid Has A Defect:

Install a new solenoid.

4. Starter Motor Has A Defect:

Make repair or replacement of starter motor.

Problem 27: Alternator Gives No Charge

Probable Cause:

1. Loose Drive Belt For Alternator:

Make an adjustment to put the correct tension on the drive belt.

2. Charging Or Ground Return Circuit Or Battery Connections Have A Defect:

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts with defects.

3. Brushes Have A Defect:

Install new brushes.

4. Rotor (Field Coil) Has A Defect:

Install a new rotor

Problem 28: Alternator Charge Rate Is Low Or Not Regular

Probable Cause:

1. Loose Drive Belt For Alternator:

Make an adjustment to put the correct tension on the drive belt.

2. Charging Or Ground Return Circuit Or Battery Connections Have A Defect:

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts with defects.

3. Alternator Regulator Has A Defect:

Install a new alternator regulator.

4. Alternator Brushes Have A Defect:

Install new brushes.

5. Rectifier Diodes Have A Defect:

Make replacement of rectifier diode that has a defect.

6. Rotor (Field Coil) Has A Defect:

Install a new rotor.

Problem 29: Alternator Charge Is Too High

Probable Cause:

1. Alternator Or Alternator Regulator Has Loose Connections:

Tighten all connections to alternator or alternator regulator.

2. Alternator Regulator Has A Defect:

Install a new alternator regulator.

Problem 30: Alternator Has Noise

Probable Cause:

1. Drive Belt For Alternator Is Worn Or Has A Defect:

Install a new drive belt for the alternator.

2. Loose Alternator Drive Pulley:

Check groove in pulley for key that holds pulley in place. If groove is worn, install a new pulley. Tighten pulley nut according to Specifications.

3. Drive Belt And Drive Pulley For Alternator Are Not In Alignment:

Make an adjustment to put drive belt and drive pulley in correct alignment.

4. Worn Alternator Bearings:

Install new bearings in the alternator.

5. Rotor Shaft Is Bent:

Make a replacement of the rotor shaft.

6. Rectifiers In The Alternator Are Shorted:

Make a replacement of the diode assembly.

Fuel System

Either too much fuel or not enough fuel for combustion can be the cause of a problem in the fuel system.

Many times work is done on the fuel system when the problem is really with some other part of the engine. The source of the problem is difficult to find, especially when smoke comes from the exhaust. Smoke that comes from the exhaust can be caused by a bad fuel injection valve, but it can also be caused by one or more of the reasons that follow:

a. Not enough air for good combustion.
b. An overload at high altitude.
c. Oil leakage into combustion chamber.
d. Not enough compression.
e. Fuel injection timing retarded.

Fuel System Inspection

To check for low fuel pressure, remove the 1/8″ Pipe Plug from the fuel filter base. Connect a pressure gauge from the 1U5470 Engine Pressure Group to the hole where the plug was removed. Run the engine at high idle and check the fuel pressure reading. The fuel pressure must be at least 105 kPa (15 psi).

A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.

1. Check the fuel level in the fuel tank. Look at the cap for the fuel tank to make sure the vent is not filled with dirt.

2. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a bad bend.

3. Install a new fuel filter. Clean the primary fuel filter.

4. Remove any air that may be in the fuel system. If there is air in the fuel system, use the priming pump and open the drain valve on the fuel injection pump housing until fuel without air comes from the drain line.


NOTICE

When fuel injection lines are loosened or tightened on the fuel injection nozzles, two wrenches must be used. The nozzle must be held with a wrench or damage to the nozzle can result.


To remove air from the fuel injection lines, loosen the fuel line nuts on the fuel injection nozzles 1/2 turn. Move the governor lever to the low idle position. Crank engine with the starter motor until fuel without air comes from the fuel line connections. Tighten the fuel line nuts.

NOTE: The fuel priming pump will not give enough pressure to push fuel through the reverse flow check valves in the fuel injection pumps.

Checking Engine Cylinders Separately

An easy check can be made to find the cylinder that runs rough (misfires) and causes black smoke to come out of the exhaust pipe.

Run the engine at the speed that is the roughest. Loosen the fuel line nut at a fuel injection pump. This will stop the flow of fuel to that cylinder. Do this for each cylinder until a loosened fuel line is found that makes no difference in engine performance. Be sure to tighten each fuel line nut after the test before the next fuel line nut is loosened. Check each cylinder by this method. When a cylinder is found where the loosened fuel line nut does not make a difference in engine performance, test the injection pump and fuel injection nozzle for that cylinder.

Temperature of an exhaust manifold port, when an engine runs at low idle speed, can also be an indication of the condition of a fuel injection nozzle. Low temperature at an exhaust manifold port is an indication of no fuel to the cylinder. This can possible be an indication of a nozzle with a defect. Extra high temperature at an exhaust manifold port can be an indication of too much fuel to the cylinder, also caused by a nozzle with a defect.

The most common defects found with the fuel injection nozzles are:

1. Carbon on tip of the nozzle or in the nozzle orifice.
2. Orifice wear.
3. Steel wire brushing of nozzle tip.

Testing Fuel Injection Nozzles

NOTE: For more information on the 5P5140 Nozzle Testing Group see, Special Instruction, Form No.SEHS7292.


NOTICE

Be sure to use clean SAE J967 Calibration Fluid when tests are made. Dirty test fluid will damage components of fuel injection nozzles. The temperature of the test fluid must be 18 to 24°C (65 to 75°F) for good test results.



NOTICE

Do not test nozzles unless you have the correct service tools.


5P4150 Nozzle Testing Group
(1) 8N7005 Nozzle Assembly. (A) 5P7448 Adapter. (B) 5P4146 Gauge, 0 to 6900 kPa (0 to 1000 psi). (C) 6V2170 Tube Assembly. (D) 2P2324 Gauge, 0 to 34 500 kPa (0 to 5000 psi). (E) Gauge protector valve for 2P2324 Gauge. (F) FT1384 Extension. (G) Gauge protector valve for 5P4146 Gauge. (H) On-off valve. (J) 8S2270 Fuel Collector. (K) Pump isolator valve.

Extra Valve
(L) Gauge protector valve (must be in open position at all times).

The fuel injection nozzle is not to be disassembled for cleaning or adjustment. Do the tests that follow to determine if the nozzle performance is acceptable.

Valve Opening Pressure Test.Flush the Nozzle.Tip Leakage Test.Orifice Restriction Test.Bleed Screw Leakage Test.

Nozzle Preparation for Test

Before fuel injection nozzle (1) can be tested, all loose carbon around the tip of the nozzle must be removed with the 8S2258 Brass Wire Brush (M).

Removing Carbon Dam
(1) Fuel injection nozzle. (2) Carbon dam. (3) Seal.

Remove carbon dam (2) with needle nose pliers and remove seal (3) from the nozzle.


NOTICE

Do not use a steel brush or a wire wheel to clean the nozzle body or the nozzle tip. Use of these tools can cause a small reduction of orifice size, and this will cause a large reduction in engine horsepower. Too much use of the 8S2258 Brass Wire Brush will also remove the coating that is on the nozzle for protection.


Clean the groove for carbon seal dam (2) and the body of the nozzle below the groove with the 8S2258 Brass Wire Brush (M). Remove the carbon, but be sure not to use the brush enough to cause damage to the body of the nozzle.

NOTE: A change in color in the area below the groove is normal and does not effect the body of the nozzle.

8S2245 Cleaning Kit
(M) 8S2258 Brass Wire Brush. (N) 6V4979 Carbon Seal Tool. (P) 8S2250 Nozzle Holding Tool.

Fuel Injection Nozzle
(4) Bleed screw and seal.

Remove bleed screw and seal (4) from the nozzle.

NOTE: The bleed screw and seal must be removed for all tests except the Bleed Screw Leakage Test.

Valve Opening Pressure Test (VOP)

1. Install 6V2170 Tube Assembly (C) to the tester.

2. Install fuel injection nozzle with 5P7448 Adapter (A) on tube assembly (6). Position the bleed screw hole toward the tester and in line with 6V2170 Tube Assembly (C). This will make the fuel spray pattern horizontal. Be sure the nozzle tip is down and extends into FT1384 Extension (F) and 8S2270 Fuel Collector (J).

------ WARNING! ------

When fuel injection nozzles are tested, be sure to wear eye protection. Test fluid comes from the orifices in the nozzle tip with high pressure. The test fluid can pierce (go through) the skin and cause serious injury to the operator. Keep the tip of the nozzle pointed away from the operator and into the 8S2270 Fuel Collector and FT1384 Extension.

--------WARNING!------

Nozzle Ready For Test
(E) Gauge protector valve. (H) On-off valve. (K) Pump isolator valve.


NOTICE

Put a shop towel around the upper part of the nozzle to take in any fuel leakage.


3. Close on-off valve (H). Open pump isolator valve (K).

4. Open gauge protector valve (E). Operate the pump to make a slow increase in pressure until the valve in the fuel injection nozzle just starts to open. Read the maximum gauge pressure at the instant fluid flows from the tip.

NOTE: It is possible for the pressure reading of the gauge to go down fast if the valve makes a noise (chatters) when it opens. It is also possible for the pressure reading of the gauge to be almost constant when the valve in the fuel injection nozzle opens.

NOTE: The valve in the fuel injection nozzle can be good and still not make a noise (chatter), or not have a very fine vapor (spray) from the orifices in the tip of the fuel injection nozzle during Step 4.

If the opening pressure is not within specifications, do not use the fuel injection nozzle again.

Flush the Nozzle

1. Close gauge protector valve (E). Close on-off valve (H). Open pump isolator valve (G).

NOTE: Make sure nozzle extends inside and below the top of FT1384 Extension (F).

2. Operate the pump rapidly for three full strokes.

Tip Leakage Test

1. Remove all fuel from the nozzle tip and body with a clean cloth.

2. Put a clean cloth around the body of the nozzle to take in any leakage from the bleed screw hole and prevent any fuel leakage to drain down to the tip of the nozzle.

Nozzle Ready For Test
(E) Gauge protector valve. (H) On-off valve. (K) Pump isolator valve.

3. Open gauge protector valve (E). Close on-off valve (H). Open pump isolator valve (K).

4. Make and hold for 15 seconds a pressure of 1380 to 2000 kPa (200 to 290 psi) less than the opening pressure measured in the VOP Test and make a note of the number of drops that fall.

5. If the nozzle is not within specifications, DO NOT USE THE NOZZLE.

Orifice Restriction Test

1. Close gauge protector valve (E) and on-off valve (H). Open pump isolator valve (K).

2. Point the tip of the fuel injection nozzle into the 8S2270 Fuel Collector and FT1384 Extension. Be sure the bleed screw hole is positioned toward the tester and is in line with 6V2170 Tube Assembly (C). This will make the fuel injection nozzle be 15° from vertical and the spray pattern will be horizontal.

3. Make a rapid increase in pressure and look at the orifice discharge (shape of discharge) when fluid begins to flow through the fuel injection nozzle. The discharge must be the same through all nine orifices. Any change either vertically or horizontally, is an indication of a bad nozzle.

Good Nozzle (Use Again)

Typical Discharge For Orifice With A Restriction (Replacement Necessary)

Typical Discharge With Horizontal Distortion (Replacement Necessary)

Typical Discharge With Vertical Distortion (Replacement Necessary)

Bleed Screws For Fuel Injection Nozzle

Bleed Screw Leakage Test

1. Install bleed screw (4) and the seal (washer) in the fuel injection nozzle. Tighten a type (A) bleed screw to 0.9 ± 0.1 N·m (8 ± 1 lb in). Tighten a type (B) or (C) bleed screw to 1.8 ± 0.2 N·m (16 ± 2 lb in). (Use the 6V4980 Torque Screw Driver to tighten the bleed screw to the correct torque.)


NOTICE

Do not tighten the bleed screw more than the torque shown. The bleed screw or seal can be damaged.


2. Put the tip of the fuel injection nozzle down inside the 8S2270 Fuel Collector and FT1384 Extension.

3. Close on-off valve (H). Open gauge protector valve (E) and pump isolator valve (K).

4. Pump the tester until fuel injection nozzle is full of fluid and the pressure on the gauge is 12 800 to 14 800 kPa (1870 to 2165 psi).

NOTE: 15 or 20 strokes of the pump can be necessary for the pressure to get to 12 800 to 14 800 kPa (1870 to 2165 psi).

5. If there is leakage, replace the sealing washer. Inspect the washer face of the bleed screw for damage, replace if needed. Test the nozzle again. If there is still leakage, the fuel injection nozzle must be replaced.

6. If no fuel leakage is found, the fuel injection nozzle is acceptable. Put a new seal (3) on the nozzle. Install a new carbon dam (2) in nozzle groove with 6V4979 Carbon Seal Tool (N).

Installing Carbon Dam
(2) Carbon dam. (3) Seal. (N) 6V4979 Carbon Seal Tool.

Fuel Injection Lines

Fuel from the fuel injection pumps goes to the fuel injection nozzles through the fuel injection lines.

When fuel injection lines are disconnected or removed, always put caps or plugs on the ends to keep dirt out of the lines. When fuel injection lines are installed, be sure all clamps and dampers are installed in their original location.

The nuts that hold a fuel injection line to an injection nozzle and injection pump must be tightened to the correct torque. If the nut is loose, fuel will leak from the connection. If the nut is tightened too tight, the inside diameter of the line will become smaller and cause a restriction to the flow of fuel in the line. Use a torque wrench and a 5P144 Fuel Line Socket to tighten the fuel injection line nuts to 40 ± 7 N·m (30 ± 5 lb ft)

------ WARNING! ------

Fuel injection lines which are bent, damaged or rubbing can leak and cause a fire. Replace any lines which have damage or leaks that cannot be corrected when tightened to the correct torque.

--------WARNING!------

Checking The Plunger And Lifter Of An Injection Pump

NOTE: There are no different size spacers available to adjust the timing dimension of the fuel injection pumps. If the pump plunger or the lifter is worn, they must be replaced. Because there is no adjustment to the timing dimension possible, there is NO OFF ENGINE LIFTER SETTING PROCEDURE.

When there is too much wear on the fuel injection pump plunger, the lifter may also be worn and there will not be good contact between the two parts. To stop fast wear on the end of a new plunger, install new lifters in the place of the lifters that have wear.

Wear Between Lifter And Plunger
Fig. A. Illustrates the contact surfaces of a new pump plunger and a new lifter. In Fig. B the pump plunger and lifter have worn considerably. Fig. C shows how the flat end of a new plunger makes poor contact with a worn lifter, resulting in rapid wear to both parts.

An injection pump can have a good fuel flow coming from it but not be a good pump because of slow timing that is caused by wear on the bottom end of the plunger. When making a test on a pump that has been used for a long time, use a micrometer and measure the length of the plunger. If the length of the plunger is shorter than the minimum length (worn) dimension given in the chart, install a new pump.

Posted in D6Tagged