Hi there,
The fuel injection system relay is located in dash fuse box, item E.
When problem occurs, you need to check if it sparks that is missing or fuel related. Unplug a spark plu wire and attach a spark plug, ground it to the engine and crank. If sparks are not available, it could be the crank angle sensor that is intermittently failing.
You can try accessing the diagnostic to find if any codes are stored in system.
FUEL INJECTION, IGNITION & TURBO SYSTEMS
Fuel injection, ignition and turbo systems each feature a self-diagnostic function for fault tracing. A common diagnostic unit, located in engine compartment behind left strut assembly, is used to retrieve codes from each control unit. Diagnostic unit is equipped with an LED indicator, activation button and function select cable.
Diagnostic unit output socket No. 2 is used for fuel injection. Socket No. 6 is used for ignition system. Socket No. 5 is used for turbo system. Once selector cable has been inserted in correct slot, depressing button once, twice or 3 times selects from one of 3 control (fault tracing) functions. Faults stored in either ECU memory are read by means of a system of LED flashes.
Diagnostic system for fuel injection ECU stores 17 different fault codes. Ignition ECU stores 9 fault codes. Turbo ECU stores 8 different fault codes. All fault codes have 3 digits. Each can range from 1-to-4. Example of 3-digit code: 4-1-3. Since all codes have 3 digits, each code requires 3 series of flashes. For easier reading, a 3-second interval separates each digit of the code.
Sorry if my earlier instructions were not clear. Whe code 1-1-1 shows, it means there are no codes stored. You should not have reset but continue with 2. Drive the vehicle around and redo the test again. If no codes are present, the problem should not be related with the PCM sensor circuit. It could be relays or wirings, fuel pump etc. Further test would have to be carried out.
Here is a description of the details.
Retrieving Codes
1. Locate the diagnostic unit and remove its cover. Connect selector cable to socket No. 2. Turn ignition to ON position. Enter control function No. 1 (retrieve codes) by pressing push button one time for at least one second and no more than 3 seconds.
2. Watch red LED and count number of flashes in 3-flash series. Flash series are separated by 3- second intervals. See Fig. 2 . Note all codes. Only 3 separate codes can be stored at once. If no codes are stored, LED will flash 1-1-1, indicating fuel system is operating properly.
3. If a fault code is received, note them for reference. Depress push button again and check for additional codes. Depress push button a third time if necessary. If first code repeats, no other codes are present.
4. Diagnostic system memory is full when 3 codes are present. Those 3 codes must be repaired before further codes can be retrieved.
Workshop owner
Diploma in Automotive Engineering, 30 years working experience.
Sorry for getting back to you late.
No, you need not turn key off. Just keep a record of the diagnostic procedure and follow accordingly and you should be able to get into diagnostics.
Yes, you can try all sockets to check if any codes from fuel or ignition are present.
If none are found and you are still not able to start, it would not be from the control system circuits. It could be a loose connection with the relays.
Checking the fuel pressure would be best done at the return hose. Unplug the return hose and if fuel comes out when cranking, the fuel pump should be working.
To test the sparks, it would be easier if you have someone helping you and to attach a spark plug would be the easiest. A spare spark plug would do. A screw driver inserted into the plug wire socket can be used as substitute, hold it about 1/4 inch away froma ground on the engine. When testing, always ground to engine and NEVER use the battery terminals to short it, it can blow up the battery. sparks should be bright blue and if it is orange or dull yellow, the ignition coil is weak and that can cause difficult or non starting.
From what you have done, I believe it is a loose connection somewhere and could be a failing relay which is working after some jolting from unplugging and plugging back in. If it is a relay, problem should be back in no time. If it is loose connections, it should take a longer time to return or might not even come back again.
You are welcomed and thank you for the bonus.
It has been a pleasure working with you.
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Have a nice day.