Car wiring question

My 1995 Honda Civic has no spark when tested with ST125 tester. I wonder if the main relay would cause the problem since my NOID light tester blinked when I tested the injectors? How do I test if the main relay is good? There is also a presence of oil in my distributor and I wonder if my distributor igniter or coil is the culprit? Your help will be appreciated.

Vehicle wiring advice

The Honda main relay is use to power up your coil and ecm but the quickest way to test that is to listen to your fuel pump if you can hear it come on when you turn your key to the on position. The main relay does it thru the yellow black wire that powers the injector and the green yellow wire that goes to pin #7 at your computer. However, the quickest way to check if the main relay is working is to watch the dash “engine service” light. It should come on when you turn the key on and quit. If it stays on, either the main relay or ecu (computer) is bad and you can find that if you have a code.

The coil can be checked quickly by removing the cap of the distributor and checking the negative side of the coil with a test light. If you crank it and the test light blinks, it means the module called igniter is working and the coil is bad. Make sure you have 12 volts going to the coil on the positive side with key on.

The presence of oil in your distributor will usually make the sensors inside the distributor fail and the most common symptom of that is there will be no injector signal which points to a bad crank sensor or cam sensor. When this happens, replace the sensors too or the complete distributor.

Notes

It is a common practice among garages to change BOTH coil and igniter when either one of them fails. Bad spark plugs usually makes the coil go bad and make sure to change them when servicing the distributor including plug wires, cap and rotors. Always buy OEM parts if you can to avoid repeated failures.

Disconnect battery negative terminal everytime you work any electrical component.