Are the readings within specification?

Step

Action

Decision

DIAGNOSTIC:

Yes. Step 8

See Section Cylinder Performance Analyzer Diagnostics for Engine Misfires below.
7

No. Step 8
Did the CPA tool flag a cylinder misfiring at idle?

Step

Action

Decision

DIAGNOSTIC:

1.CPA Flagged no Misfires and RCT (or
MCT) is within specification; Step 9

Relative Compression Test

8

Note: 2007 - 2009 MaxxForce 7 the RCT may not be accurate or has an inability to
2. CPA Flagged a Misfire and RCT (or
document cylinder compression. If this is the case then perform a manual compression MCT) is within specification; Step 10
test on the suspected bank ONLY (Both if Required). General Specification Rule - If
Cylinders are within 40 psi of each other after FOUR revolutions, compression is not an
issue.
3. CPA Flagged a Misfire and RCT (or
In ServiceMaxx under "Tests", "KOEO Tests", perform the "Relative Compression Test". MCT) is out of specification; Step 10
Specification: All cylinders are within 7 RPM of each other.

Step
9

Action

Decision

DIAGNOSTIC:

Yes. See the Fuel System Cleaning
section below.
No. Complete any other work needed
and release unit to customer.

Engine misfire is not present. Re­evaluate engine condition, operation, and "misfire"
operating conditions.
Other Possibilities:
1. Engine "misfire" at elevated RPMs
2. Engine surging due to other condition (EGR, ITV, FRP, Low Side Fuel Pressure,
Aftertreatment, Elevated Oil Level, etc.)

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 6/1/2015

IK1201222 ­ MaxxForce 7 Misfire Diagnostics

Page 4 of 7

After reevaluation does the engine still qualify for misfire diagnostics?

Step

Action

Decision

DIAGNOSTIC:

Yes. Replace components and
reassemble the engine. Reset the fuel
pressure adaptives; Step 11

Remove the valve cover and injector. Inspect the injector tip, rocker arms, and push
tubes.
10

Step

11

Are any components damaged or worn?

No. Replace injector reassemble engine.
Reset the fuel pressure adaptives; Step
NOTE: If the injector tip is heavily damaged the cylinder/piston may
exhibit unrepairable damage, if this is the case do not replace components at this time 11
and proceed to Step 12

Action

Decision

DIAGNOSTIC:

Yes. Return to Step 7, if the CPA tool
flags the same cylinder, Step 12

Does the engine still misfire?
No. Repair complete, release truck

Step

12

Action

Decision

DIAGNOSTIC:

Yes. Step 13

Remove the engine oil pan and inspect for debris and damage to the base engine
Lifters, Cam, Cylinder Walls, Crankshaft, or Pistons/Rods?

No. Step 14

Were any issue noted?

Step

Action

Decision

DIAGNOSTIC:

Yes. Open a case file with Navistar's
Technical Support group with all relevant
information, pictures, parameter file and
recordings for further assistance.

Does the engine fall under any of the following conditions?
13

Step

14

1.
2.
3.
4.

Severe Camshaft Lobe Damage
Severe Cylinder Wall Damage
Severe Crankshaft Damage
Severe Crankcase Damage

No. If related and can be corrected
proceed with repairs, if not Step 14

Action

Decision

DIAGNOSTIC:

Yes. Step 15

Remove the cylinder head per the Engine Service Manual and Perform Base Engine
Inspections.
No. Step 16
Were any Issues Noted?

Step

Action

Decision

DIAGNOSTIC:

Yes. Open a case file with Navistar's
Technical Support group with all relevant
information, pictures, parameter file and
recordings for further assistance.

Does the engine fall under any of the following conditions?
15

Step
17

1.
2.
3.
4.

Severe Camshaft Lobe Damage
Severe Cylinder Wall Damage
Severe Crankshaft Damage
Sever Crankcase Damage

No. If related and can be corrected
proceed with repairs, Step 16

Action

Decision

DIAGNOSTIC:

Yes. If non-condemning replace/repair
components per the Engine
Service Manual reassemble the engine. If
the issue has not been resolved by this
time open a case file with Navistar's
Technical Support group with all relevant

Remove the piston assembly and inspect.
Are any issues noted?

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 6/1/2015

IK1201222 ­ MaxxForce 7 Misfire Diagnostics

Page 5 of 7

information, pictures, parameter file and
recordings for further assistance.
No. Open a case file with Navistar's
Technical Support group with all relevant
information, pictures, parameter file and
recordings for further assistance.

CYLINDER PERFORMANCE ANALYZER DIAGNOSTICS FOR ENGINE MISFIRES
NOTE: ON THE MAXXFORCE 7 THE CPA TOOL IS VERY ACCURATE IN FLAGGING ENGINE MISFIRES AT IDLE ONLY. ELEVATED ENGINE
SPEEDS BRINGS HIGHER TORSIONAL VIBRATIONS WHICH CAN AND WILL IMPROPERLY FLAG CYLINDERS FOR A MISFIRE. THE SAME
APPLIES FOR UNDER A LOAD AND DRIVING.

Connecting the CPA Tool
The Camshaft Position Sensor and Crankshaft Position Sensor connectors are reversed, in comparison to the DT, 9 and 10. On the CPA box, the
BNC cables need to be connected such that the correct sensor is feeding the correct port (Crank to Crank, Cam to Cam)--the crankshaft position
sensor is located on the right (passenger) side of the engine towards the front just above the oil pan and the camshaft position sensor is located on
the left (drivers) side of the engine.
If needed see the following iKNow article for further CPA instructions IK1200812 - Diagnosing Cylinder Performance Related Symptoms Using the
CPA Tool

CPA Software Preparation

Figure 1: Cylinder Performance Analyzer Information Table
Item 1: Base Engine Class V8

1. After connecting the CPA tool to the truck and laptop, launch the Engine Cylinder Performance Analyzer software from ServiceMaxx. Make sure
the base engine class is selected as V8 before continuing see Figure 1.

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 6/1/2015

IK1201222 ­ MaxxForce 7 Misfire Diagnostics

Page 6 of 7

Figure 2: Cylinder Performance Analyzer Information Table
Item 1: Base Engine Class V8

2. If done properly, the engine misfire display figure shows an 8 cylinder engine shown in Figure 2.

Figure 3: Cylinder Performance Analyzer MisFire
Indicator

Attention
The EPA13 MaxxForce 7 has a montior called the Injector Performance Analyzer, this monitor runs after every key cycle during the first
two minutes of idling time. Before anaylzing performance with the CPA tool allow the engine to idle for two minutes for the monitor to
complete its analysis and return the engine to a normal idling pattern.
3. With the CPA tool, perform the standard "Signal Check." After passing the signal check, begin recording the engine data during the time of the
misfire complaint (Cold Idle or Hot Idle). The same standard misfire display follows the same rules as the DT, 9 and 10 Engines and can be seen in
Figure 3.

Return to Step 7

REPAIR STEPS
Fuel System Cleansing

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 6/1/2015

IK1201222 ­ MaxxForce 7 Misfire Diagnostics

Page 7 of 7

1. Warm the engine to operating temperature
2. Connect the clean fuel source 15­637­01
3. Add 1/2 bottle Fuel System Cleaner to the clean fuel source and mix throughly with a full container
4. Run the engine high idle until nearly all the fuel has been used up (Do not run it dry and air bound the system)
5. If the truck has atleast a 1/2 tank of fuel add the remaining cleanser to the tank. If not give the customer the bottle to add before the next fill up

WARRANTY INFORMATION
Warranty Claim Coding:
Group: 12000 - Engines
Noun: 313 ­ Carrier Assembly, Rocker Arm
404 - Lifter, Valve
416 - Rods, Push
563 - Injector Unit (Electrical)
137 - Piston, Pin, Lock, Bushing
192 ­ Sleeve Cylinder
051 - Crankcase
Warranty Coding Manual
Standard Repair Times:
Due to extensive SRT options and requirements for the repair plans, see the Standard Repair Time Manual for specific engine/vehicle combinations.
Standard Repair Time Manual
STEP
Step 1
Step 2
Step 3 & 4
Step 6
Step 7
Step 8

Step 10
Step 12
Step 14
Step 16

DESCRITPTION
ECM Calibration
Visual Inspection
Check for DTCs & Reset Adaptives
Crankcase Pressure Test
Blow-by Test (EPA 2010)
Crankcase Breather Replacement
EPA (2010)
Cylinder Performance Analyzer
Relative Compression Test (EPA
2010)
Manual Compression Test (EPA
2007)
Rocker Arm Replacement
Injector Replacement
Oil Pan R&R
Cylinder Head Removal (EPA 2007)
Cylinder Head Removal (EPA 2010)
Piston and Rings Replace

MANUAL SECTION
ELECTRONIC CONTROL MODULE (ECM OR ECM/IDM) - ENGINE PROGRAM
ELECTRONIC ENGINE PERFORMANCE, DIAGNOSE
ELECTRONIC ENGINE PERFORMANCE, DIAGNOSE
ELECTRONIC ENGINE PERFORMANCE, DIAGNOSE
ELECTRONIC ENGINE PERFORMANCE, DIAGNOSE
CRANKCASE BREATHER HOUSING ASSEMBLY, REPLACE
T­Time (0.7 Hours) CYLINDER PERFORMANCE ANALYZER (CPA) TOOL, DIAGNOSIS
ELECTRONIC ENGINE PERFORMANCE, DIAGNOSE
ELECTRONIC ENGINE PERFORMANCE, DIAGNOSE
ROCKER ARM, PUSH RODS AND/OR VALVE BRIDGES (V-ENGINES), REPLACE
FUEL INJECTOR(S) (ELECTRONIC ENGINES), REPLACE
OIL PAN AND/OR GASKET, REPLACE
CYLINDER HEAD GASKET (V-ENGINES), REPLACE
CYLINDER HEAD OR REPLACE GASKET (V ENGINES), R&R AND OR REPLACE
PISTON RINGS, REPLACE

OTHER RESOURCES
Master Service Information Site

Hide Details

Feedback Information
Viewed:

5421

Helpful:

30

Not Helpful: 6
No Feedback Found

Copyright © 2015 Navistar, Inc.

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 6/1/2015