How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask iauto8 Your Own Question
iauto8, ASE Certified Technician
Category: Car
Satisfied Customers: 137
Experience:  15 year ASE Auto Technician. European import specialist.
Type Your Car Question Here...
iauto8 is online now
A new question is answered every 9 seconds

I have a 1990 Honda Civic wagon, which has almost 226,000 miles

This answer was rated:

I have a 1990 Honda Civic wagon, which has almost 226,000 miles on it. About twice a week it cranks but won't start and then it usually starts 5 minutes to two hours later. I have taken it to two mechanics I trust. One did a tune-up (spark plugs etc.) and an oil change. The other replaced the fuel pump and fuel filter and checked the pump relay. I still have the intermittent start problem. Is it electrical? Any ideas? And would it help to take it to a mechanic who has a diagnostic computer?

iauto8 :

There are 2 problems this car has that fit your description. One would be the main relay is failing. The other would be the ignition distributor is going bad. I will post test procedures for both. If the main relay has not been replaced yet I would do that first even if you are unable to verify with tests due the problem being intermittent. Chris.......

iauto8 :


1. Verify that the Check Engine Light (CEL) comes on 2 seconds and goes out when the key is first turned on.

2. The Programmable Fuel Injection (PGM-FI) main relay is located under the driver's side of the dash, way up high above the left kick panel. Always verify powers and grounds to the PGM-FI main relay. If there is a power problem, test the ignition switch for correct operation.

3. The Yellow/Black (YEL/BLK) wire from the main relay powers up the fuel pump. The Engine Control Module (ECM) will ground the Green/Black (GRN/BLK) wire so the second half of the relay operates and supplies power to the fuel pump.

4. If the problem will not act up, remove the PGM-FI main relay and leave it connected, heat the PGM-FI main relay up with a heat gun and see if the vehicle fails to start. If the vehicle fails to start, replace the relay, as it is a very common failure.

iauto8 :


1. Test the Yellow (YEL) wire at the igniter. It should have battery voltage with the Key On Engine Off (KOEO) and the coil negative wire should have battery voltage.

2. Test the Yellow/Green (YEL/GRN) wire on the igniter. It should have 9 to 12 volts produced by the igniter. If the Yellow/Green wire has the correct voltage, the Engine Control Module (ECM) should pulse the voltage to ground to create spark.

3. To test the signal, back probe the Yellow/Green wire using a lab scope or a dwell meter. Look for a square wave signal to ground or a dwell reading of 10 to 14 degrees. If the signal is good, check for a trigger signal on coil negative. If the trigger signal is present, replace the ignition coil.

iauto8 and 6 other Car Specialists are ready to help you

Related Car Questions