  |
FUEL INJECTION TROUBLESHOOTING TIPS
This page provides troubleshooting tips for various fuel injection trouble symptoms. Experience with fuel injection
has shown that most car problems attributed to the system are really problems with other systems, such as ignition,
engine, electrical, etc. Therefore before troubleshooting the fuel injection system you should road test the car
and then check the following:
- Condition of battery
- Condition of spark plugs
- Ignition timing
- Valve timing
- Engine compression
- Idle speed
Whenever possible an HC-CO test should be performed using an infrared analyzer. The test results can be a valuable
aid to proper troubleshooting of the fuel injection system. After you have confirmed that these are correct, find
the symptom which best describes the condition. Then, follow the proper procedures to isolate the car problem.
While testing, you may see " If test light does not light check wires indicated in diagram. If wires are good,
replace component." The wires to be checked on the diagram are indicated by the heavier lines. Many car problems
related to performance are simply centered around wiring of the fuel injection system. To check the wires use an
ohmmeter and check continuity from pin to pin.
The electrical system can be checked using only an ohmmeter and a test light. A voltmeter can be used instead of
a test light to obtain specific readings. When connecting test equipment make sure you are on the correct terminal
and not touching any other wire. Make sure you have a good ground point when required.
Whenever it is necessary to open the fuel system you may see WARNING FIRE HAZARD displayed on the OBD-II troubleshooting
module. Before opening the system, relieve fuel pressure as follows:
- Remove fuel tank cap
- Disconnect vacuum hose from fuel pressure regulator
- Using a hand pump apply about 25 lb to the pressure regulator
- Note: Fuel pressure will be released into the fuel tank through the fuel return hose
Use care when working with an open fuel system. Do not smoke. Keep open flame away. Make sure fuel does not
in contact with skin, eyes, or hot surfaces such as exhaust manifold. Be careful of sparks from battery or ignition
system. A work area with adequate ventilation should be used.
The fuel injection system is highly susceptible to contamination. Make sure the area is clean whenever you remove
either the cold start valve or injectors or disconnect a fuel hose. Use extreme care so that no dirt enters the
fuel system, thereby making your car problem worse than it was to begin with. A fuel injection system electrical
diagram should be used to assist you in component identification and system troubleshooting.
Copyright 2000. Ted Neal, Inc. Please e-mail me if you have any questions
about this website or would like to suggest a link. Thank you.
|
