Briggs & Stratton BIG BLOCK EFI, Руководство по ремонту

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Section 2: Troubleshooting DTCs 45
Step Action Yes No
1
1. Check fuel fi lter and fuel lines for dirt, debris or
other restriction.
2. Is a problem found?
Repair. Go to step 2.
2
1. Check fuel pressure.
2. Is fuel pressure 38-43 psi (262-296 kPa)?
- Go to step 3.
3
1. Verify that fuel fi lter is not clogged or restricted,
and that fuel pump is operating properly (see
Mechanical Diaphragm Fuel Pump or Electric
Lift Fuel Pump , Volumetric Test , in Section 5).
2. Is a problem found?
Repair. Go to step 4.
4
1. Check for vacuum and exhaust leaks.
2. Is a leak found?
Repair. Go to step 5.
5
1. Check for faulty fuel injector(s).
2. Are faulty fuel injector(s) found?
Repair. Go to step 6.
6
1. Replace faulty HO
2
sensor.
2. Is problem corrected?
-
Contact engine
manufacturer.
DTC P0174 Power Enrichment (PE) Lean Fuel Condition
Scan and Non-Scan Diagnostics
Circuit Description
The PE mode is initiated in higher load run-
ning conditions. The ECM uses the MAP and
CKP sensor inputs to know when to go into PE
mode. PE fueling provides for optimal perfor-
mance and maximum power. It also prevents
against excessive exhaust valve and engine
temperatures.
Diagnostic Aids
If DTC P0174 is set, the ECM is detecting an
overly lean condition under heavy load.
Always clear DTCs after performing repairs.