Engine Power Output Low
Step
Action
Yes
No
1
Perform OBD System Check.
Are any DTCs found?
Go to applicable DTC Table.
Go to step 2.
2
Perform a careful visual check.
Is a problem found?
Repair
Go to step 3.
3
Check the following fuel system components for dirt, water, or other
contaminants.
•
Fuel tanks
•
Fuel filter
•
Fuel lines
•
Fuel pumps
Is a problem found?
Repair
Go to step 4.
4
Verify that there is fuel flow flow from the mechanical fuel pump to
the fuel injector.
Is a problem found?
Repair
Go to step 5.
5
Verify crankcase oil is at the correct level.
Is a problem found?
Add crankcase oil.
Go to step 6.
6
Verify air filter element is clean and dry.
Is a problem found?
Replace air filter element.
Go to step 7.
7
Verify engine is not supporting a greater load than intended for its
application? Check for the following:
•
Damaged drive belt.
•
For mowers, verify blades are not restricted by debris.
•
Faulty pulley bearing(s).
Is a problem found?
Repair
Go to step 8.
8
Verify spark plug is:
•
Gapped properly.
•
Not gas fouled.
•
Not excessively worn.
Is a problem found?
Repair
Go to step 9.
9
Verify exhaust is not restricted.
Is a problem found?
Repair
Go to step 10.
10
Check engine for the following mechanical problems:
•
Low compression.
•
Leaking cylinder head gaskets.
•
Proper valve set up.
See Repair Manual.
Is a problem found?
Repair
Go to step 11.
69
Not for
Reproduction
Summary of Contents for 25E300
Page 1: ...Vanguard EFI Diagnostics and Repair 25E300 REPAIR MANUAL N o t f o r R e p r o d u c t i o n...
Page 18: ...Model 25E300 EFI Component Locations 19 N o t f o r R e p r o d u c t i o n...
Page 26: ...Speed vs Voltage Table 8 27 N o t f o r R e p r o d u c t i o n...
Page 61: ...25E300 Wiring Harness Diagram 62 vanguardpower com N o t f o r R e p r o d u c t i o n...
Page 62: ...63 N o t f o r R e p r o d u c t i o n...
Page 88: ...Model 25E300 Fuel Hose Location and Routing Tankless 89 N o t f o r R e p r o d u c t i o n...
