Troubleshooting a No Spark Problem in Honda Accord

Honda Accord
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Not every problem with an engine refusing to start is the same. That's why we call figuring out what's wrong with your car "troubleshooting" rather than just "fixing." Before we can fix the no-start problem—in this case in a 1996 Honda Accord EX, which serves as a good example—we have to figure out what's causing the engine to refuse to start.

No Spark

Here is what this owner experienced:

My 1991 Honda Accord EX has 178,000 miles with little or no problem until now. Driving home the other night it just shut off as though I turned the car off. No sputter no nothing. It cranks and cranks but would not and will not start. Had the car towed home and the next day I replaced the fuel pump because I couldn't hear it making that whirling noise, so I thought for sure that was the problem. Well, it wasn't I guess. It still cranks like it wants to start, but will not. I can hear the new fuel pump operating now. Could it be the main relay? Please help.

 

Since you probably don't have access to a proper fuel pressure meter, you'll have to use your intuition. Most fuel pumps will make a quiet hum to let you know they are working, but a loudly buzzing pump is often an indication that it's on the way out (meaning it's producing far less fuel pressure than you need for the engine to run properly) or it's dead but still receiving electrical current. 

In this case, the owner replaced the fuel pump, but the problem was elsewhere. Don't be discouraged when this happens. Although it costs more money when you have to replace multiple parts in your car to solve a problem, this is the burden of the DIY mechanic. And think of all the money you've saved by working on your own car! 

When the Main Relay Goes Bad

A bad fuel pump causes a sputtering type of stall, not an out-and-out lack of spark. This owner's car just "quit," and one reason for that might be a problem with the main relay—an electronic device that opens and closes the fuel supply to the engine.

This happens most often when the car is overheated, and it's something the novice can certainly troubleshoot.  

Other Causes of a no-Spark Engine

There are three primary things that will keep the engine from getting a spark: A bad ignition coil, a bad igniter, and a bad distributor.

To check the ignition coil, measure the resistance between the + terminal (black/yellow wire) and the - terminal (white/blue wire) of the coil.

The resistance should be about 0.6 to 0.8 ohms at 70° F. Then check the resistance between the + terminal (black/yellow wire) and the coil wire terminal. It should be about 12,000 to 19,200 ohms at 70° F. It can also be bench tested out of the car.

As for the igniter, if the tachometer is working, then the igniter is okay. Here is the procedure for checking the igniter.

  1. Remove the distributor cap, the rotor, and the leak cover.
  2. Disconnect the black/yellow, white/blue, yellow/green, and blue wires from the igniter unit. 
  3. Turn the ignition switch ON and check for battery voltage between the black/yellow wire and body ground. If there is no battery voltage, check the black/yellow wire between the ignition switch and the igniter unit. If there is battery voltage, proceed to step 4. 
  4. Turn the ignition switch ON and check for battery voltage between the white/blue wire and body ground. If there is no battery voltage, check the ignition coil for proper operation or for an open circuit on the white/blue wire between the ignition coil and the igniter unit. If there is battery voltage, proceed to step 5. 
  5. Check the yellow/green wire between the PGM-FI ECU and the igniter unit. 
  6. Check the blue wire between the tachometer and the igniter unit. 
  1. If all tests are normal, replace the igniter unit.

If the coil and igniter check out as good, then replace the distributor. Check for codes in the power-train control module. That will help pinpoint the problem for you.