QuestionQUESTION: i have a 1986 vg20e v6 turbo bluebird maxima trying to locate injector relay switch.fuel is running into sump oil.my thought is injectors staying open?
ANSWER: Doug,
The fuel pump relay is in the car on the drivers side. I would think a leaky injector or two. Perform a fuel pressure test and see how it looks. The pressure should come up to something like 36 psi and stay there for several minutes after you turn the key off. If it does not then you have a leaky injector or more. Pull the spark plugs and see which are really black. That is where the leaky injectors are. The ones that are gray are normal and do not require injector replacement at that cylinder.
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QUESTION: Should the red and green light stay on the computer when you turn the ignition on or is this a problem?, About injectors leaking, should i replace the Fuel pressure regulator?, Or the fuel pump? would this solve the problem of leaking injectors?, or is there another way of going about it.,
thanks in advance.
AnswerDoug,
If you have leaky injectors you need to test for them. Get a fuel pressure gauge and hook it up and check the pressure with the engine running, key on and then off. If the pressure leaks off rapidly then you probably have a leaky injector or two. Also, remove the plugs and note their condition. A really black and wet plug indicates that is where you have a leaky injector. The following is the procedure to check for computer codes and the condition of the fuel injection and engine management system for 1988 and older Nissan Computer Codes are as follows:
ENTERING SELF-DIAGNOSTICS
1) Turn ignition switch to ON position. Use a screwdriver to turn ECM diagnostic mode selector fully clockwise.
2) Wait for inspection lights to begin flashing. At this
time, inspection lights will flash mode options (i.e., one flash for Mode I, 2 flashes for Mode II, etc.). As soon as inspection light flashes desired mode number (3 flashes for self-diagnostic mode), turn mode selector off (fully counterclockwise)
3) If mode selector is kept in ON position (fully clockwise), mode selections will continuously cycle. This cycling will not erase memory.
RETRIEVING CODES
NOTE: Not all trouble codes will activate MIL (CHECK ENGINE light)
Trouble codes are read using Red LED and Green LED inspection lights on side of ECM. After selecting Mode III, trouble codes corresponding to mode will start flashing. Trouble codes are indicated by number of flashes from ECM Red LED and Green LED inspection lights. Count number of flashes. Red LED indicates first digit of code, and Green LED indicates second digit of code. For example, 3 flashes of Red LED followed by 2 flashes of Green LED indicate Code 32.
SELF-DIAGNOSTIC SYSTEM
Self-diagnostic system can be operated in any of 5 modes. Modes are manually changed using screwdriver through access port of ECM. With screwdriver turned fully clockwise, inspection lights will begin to flash. Count number of flashes. First flash is Mode I, second flash is
Mode II, etc. When desired mode has been indicated, turn screwdriver fully counterclockwise. In different modes, Red LED and Green LED perform different functions.
Mode I (Exhaust Gas Monitor)
This is normal vehicle operating mode. Green LED will indicate loop status. If Green LED is not blinking, vehicle is in open loop or a fault exists with oxygen sensor or sensor circuit. If Green LED is blinking, vehicle is in closed loop. If a malfunction occurs in Mode I, Red LED and MIL (CHECK ENGINE light) will illuminate, indicating an engine control system malfunction has occurred.
Mode II (Mixture Ratio Feedback Monitor)
In Mode II, both Red LED and Green LED are used to monitor air/fuel mixture feedback control. Green LED will function as in Mode I. In open loop, Red LED and Green LED will remain on or off. For results to be valid, vehicle must be in closed loop. In closed loop, Red LED will indicate if system is running rich (light off), lean (light on) or at ideal air/fuel ratio (blinking synchronized with Green LED)
Mode III (Self Diagnostics)
When Mode III is accessed, codes stored in ECM memory will be flashed by Green LED and Red LED on side of ECM. Red LED will flash first digit of code, while Green LED will flash second digit of code. For example: 3 flashes of Red LED followed by 5 flashes of Green LED indicate a Code 35.
Mode IV (Switch Check)
This mode is used for checking engine control systems switch status. When idle switch or starter switch is activated, Red LED will come on and go off as status changes. For vehicle speed sensor status, Green LED will remain off when vehicle speed is less than 12 MPH and
come on when vehicle speed is greater than 12 MPH.
Mode V (Test Mode)
Mode V represents a real-time diagnostic test of camshaft position sensor, ignition signal and mass airflow output signal. This mode is accessed for an in-bay running test of vehicle. Red and Green LED5 must be monitored carefully during this test, with special attention paid to number of flashes before each pause. Malfunction code will be displayed only once and will not be stored in memory. If Red LED blinks on and off evenly, a fault exists in camshaft position sensor. If Green LED flashes twice before a pause, a fault exists in airflow meter. If Green LED blinks 4 times before a pause, a fault exists in ignition signal.
Trouble Codes
Without Onboard Diagnostics (OBD-II)
11 Camshaft position sensor.
12 Mass airflow (MAF) sensor.
13 Engine coolant temperature (ECT) sensor..
14 Vehicle speed (VSS) sensor.
21 No ignition referance.
23 Throttle Valve Switch
24 Transmission Switch
31 Engine control module (ECM).- A/C, light,fan and PS switch
32 EGR sensor.- starter switch
33 Oxygen sensor.
34 Knock (detonation) sensor (3.0 L).
35 EGR temp sensor.
41 Air temp sensor.
43 Throttle position sensor (TPS).
44 Normal Operation
45 Injector leak.
51 Injector circuit (3.0 L).
55 No malfunction recorded.
