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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 4969
Experience:  Owner at DJ Wilson
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I have a problem with a QSX15 engine. the serial number is

Customer Question

Hello,
JA: Thanks. Can you give me any more details about your issue?
Customer: My name is ***** ***** I have a problem with a QSX15 engine. the serial number is ***** The injectors keep failing i have bought completely new as well as reconditioned but they keep failing. What could cause this problem?
JA: OK got it. Last thing — Technicians generally expect a deposit of about $54 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Customer: replied 1 year ago.
Did you receive the payment ok?
Expert:  Daniel Wilson replied 1 year ago.

Hi My name is***** will be glad to try to help you with this. At what intervals are these injectors failing? What are your running for fuel and do you by chance have any test results as far as the cetane level etc from a fuel quality test? what is this engine in and what year is it?

Expert:  Daniel Wilson replied 1 year ago.

What do you have logged in the ECM for fault codes?

Customer: replied 1 year ago.
The injectors fail around 50-100 hours. For fuel I run a dual tank setup. Start and shut down with regular diesel and running with vegetable oil. I have been running this setup for more than 2000 hours and this is a problem only now. There are no ecm fault codes. Once one of the injectors fails the engine starts running rough and misfires with loss of power.
Expert:  Daniel Wilson replied 1 year ago.

Thanks for the update. What modifications had to be done to the fuel system and filtration to run the vegetable oil ?

Expert:  Daniel Wilson replied 1 year ago.

Install a 400-500PSI gauge at the pump and get a pressure reading. Then check after the filter at the fuel manifold ( actuator manifold) test port. there should not be more than 75 PSI difference.

Use the correct filter(s) for your engine. It must remove a
minimum of 95 percent of free and emulsified water. It
must also have a minimum of 98.7 percent at 25-micron
particle-removal efficiency.
Cummins, Part Number(###) ###-####br />Fleetguard® Nelson®, Part Number FS1040

Expert:  Daniel Wilson replied 1 year ago.

Verify your overhead settings are correct as well.

Overhead Set QSX15
Page 6-4 Section 6 - Maintenance Procedures at 6000 Hours or 2 Years
NOTE: Read the entire procedure for overhead
adjustment before attempting to perform this operation.
Valves, injectors, and engine brakes (if equipped) must
be correctly adjusted for the engine to operate efficiently.
Valve, injector, and engine brake adjustment must be
performed using the values listed in this section.
Adjust the valves, injectors, and engine brakes every
800,000 km [500,000 mi], 10,000 hours, or 5 years
(whichever occurs first). Adjustment must be made after
any major repair. After a major repair, the adjustment
interval again becomes every 800,000 km [500,000 mi],
10,000 hours, or 5 years (whichever occurs first).
Signature, ISX, and QSX15
Valve, Brake, and Injector
Adjustment Values
Signature, ISX, and QSX15 Injector Adjustment is
8 N•m [70 in-lb]
mm in
Intake Valve 0.35 0.014
Exhaust Valve 0.68 0.027
Engine Brake 7.00 0.276
Adjust
NOTE: Make sure the engine base timing is properly set
before attempting to adjust/set the overhead. Refer to
Procedure 001-088.
All overhead valve, injector, and brake adjustments
must be made when the engine is cold (any stabilized
coolant temperature at 60°C [140°F] or below).
NOTE: After an engine rebuild or any major repair where
the injector and valve setting must be disturbed, set all
the valves and injectors and brakes.

Expert:  Daniel Wilson replied 1 year ago.

QSX15 Overhead Set
Section 6 - Maintenance Procedures at 6000 Hours or 2 Years Page 6-5
CAUTION
Do not use solvent to clean the rocker cover gasket.
Solvent can damage the gasket material and cause it
to swell.
Remove the rocker lever cover and gasket. Refer to
Procedure 003-011.
NOTE: Early engine vibration dampers are marked with
BRAKE SET 1-6, BRAKE SET 2-5, or BRAKE SET 3-4. The
engine brakes must be set at the appropriate mark on
these engines. Newer engine vibration dampers are
marked with only A, B, or C, and are adjusted with the
valves and injector on the same cylinder.
Locate the valve set marks on the outside of the vibration
damper.
The set marks are A, B, and C:
Set to mark A to adjust cylinder 1 or 6.
Set to mark B to adjust cylinder 2 or 5.
Set to mark C to adjust cylinder 3 or 4.
NOTE: Two complete revolutions are required to set all
valves, engine brakes, and injectors.
With Air Compressor:
Remove the oil fill connector from the lower gear case
cover.
Insert a 3/4-inch drive ratchet and extension into the air
compressor drive.
Rotate the air compressor drive clockwise as viewed from
the front of the engine.
WARNING
Do not pull or pry on the fan to manually rotate the
engine. To do so can damage the fan blades.
Damaged fan blades can cause premature fan failures
which can result in serious personal injury or property
damage.
The crankshaft rotation is clockwise as viewed from the
front of the engine.
The cylinders are numbered from the front of the engine
(1-2-3-4-5-6).
The engine firing order is 1-5-3-6-2-4.

Expert:  Daniel Wilson replied 1 year ago.

QSX15 Overhead Set
Section 6 - Maintenance Procedures at 6000 Hours or 2 Years Page 6-7
NOTE: Early engine vibration dampers are marked with
BRAKE SET 1-6, BRAKE SET 2-5, or BRAKE SET 3-4. The
engine brakes must be set at the appropriate mark on
these engines. Newer engine vibration dampers are
marked with only A, B, or C, and are adjusted with the
valves and injector on the same cylinder.
The valves, brakes, and the injectors on the same cylinder
are adjusted at the same index mark on the vibration
damper.
Signature, ISX and QSX15
Injector and Valve Adjustment Sequence
Set Cylinder
Bar Engine in
Direction of
Rotation
Pulley
Position
Injector Valve Brake
Start A 1 1 1
Advance to B 5 5 5
Advance to C 3 3 3
Advance to A 6 6 6
Advance to B 2 2 2
Advance to C 4 4 4
Firing Order: 1-5-3-6-2-4
Use the compressor drive or barring device to bar the
engine over in the direction of engine rotation,
clockwise as viewed from the front of the engine. Align
the A mark on the vibration damper with the pointer on the
gear cover.
NOTE: For illustrative purposes, position A is shown as
the first step. It is not necessary to start with position A,
as long as the proper sequence is followed.
Check the valve rocker levers on the given cylinder to see
if both intake and exhaust valves are closed.
NOTE: Both sets of valves are closed when the rocker
levers and the brake lever are loose. If both sets of valves
are not closed, rotate the compressor drive gear one
complete revolution, and align the A mark on the front
damper with the pointer again.

Expert:  Daniel Wilson replied 1 year ago.

Overhead Set QSX15
Page 6-8 Section 6 - Maintenance Procedures at 6000 Hours or 2 Years
Loosen the injector adjusting screw locknut on the
cylinder.
Use a dial-type torque wrench with a range of 0 to 150 inlb
to tighten the injector rocker lever adjusting screw. If the
screw chatters during setting, repair the screw and lever
as required.
NOTE: Do not use a click-type torque wrench.
Back out the adjusting screw one or two turns.
Hold the torque wrench in a position that allows you to look
in a direct line at the dial. This is to make sure the dial will
be read accurately.
Make sure the parts are aligned, and squeeze the oil out
of the valve and injector train by tightening the adjusting
screw.
NOTE: Use this initial adjustment to preload the valve
train and injector.
Tighten the injector lever adjusting screw.
Torque Value: 8 N•m [ 71 in-lb ]
Back the adjusting lever screw out 1 or 2 turns.
Retighten the injector lever adjusting screw.
Torque Value: 8 N•m [ 71 in-lb ]
Hold the injector lever adjusting screw, and tighten the
adjusting screw locknut.
Torque Value: 75 N•m [ 55 ft-lb ]

QSX15 Overhead Set
Section 6 - Maintenance Procedures at 6000 Hours or 2 Years Page 6-9
After setting the injector on a cylinder, set the valves, and
engine brakes on the same cylinder.
NOTE: Early engine vibration dampers are marked with
BRAKE SET 1-6, BRAKE SET 2-5, or BRAKE SET 3-4. The
engine brakes must be set at the appropriate mark on
these engines. Newer engine vibration dampers are
marked with only A, B, or C, and are adjusted with the
valve and injector on the same cylinder.
With the set mark aligned with the pointer on the gear
cover and both sets of valves closed on the cylinder,
loosen the locknuts on the intake and exhaust valve
adjusting screws.
Back out the adjusting screws one or two turns.
Select a feeler gauge for the correct valve lash
specification.
Valve Lash Specification
mm in
Intake 0.36 NOM 0.014
Exhaust 0.69 NOM 0.027
Insert the feeler gauge between the top of the crosshead
and the rocker lever nose pad.
Make sure the feeler gauge is completely under the
pivoting rocker lever nose pad.
Tighten the adjusting screw.
Torque Value: 0.6 N•m [ 5 in-lb ]

Expert:  Daniel Wilson replied 1 year ago.

Valves and injectors are set on the same cylinder on this engine. Let me know

Customer: replied 1 year ago.
Thank you for the fast reply. The setup allows the vegetable oil to come to 170 degrees so it lowers the viscosity. 2 aditional filters are used rated at 15micron. I will check with the gauges the fuel pressure. Should i check under load? At what rpm? If there is a difference what could cause it?
Expert:  Daniel Wilson replied 1 year ago.

Hi, Thanks for the update. We are on different time zones it seams. Pleasure to help. Click on this link for a troubleshooting bulletin and I will also gather some more info to help you with this.

Troubleshooting

Expert:  Daniel Wilson replied 1 year ago.

Click below for the fuel system testing.

Expert:  Daniel Wilson replied 1 year ago.

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