Questions and Answers

Honda Civic Injector Problem Q. Hi, your web site is great. Hope you can help me with a problem I'm having. I'm having all the symptoms off a bad main relay. Sorry I have a 1988 Honda Civic LX 1.5 liter 4 door. It has power steer/locks, A/C and has about 193,000 miles on it. Just went through the engine, main/rod bearings/timing belt, well you now all that goes into a rebuild.

The car will start and run sometimes, but not others, good spark, good fuel pressure, but plugs are dry when it won't start. All the symptoms of a bad main relay. Tested the relay and wiring both tested fine. I tried another main relay and another computer and still am having the same problem. Followed test sequence in Honda manual for code 16. Got to the part where I'm supposed to hook up the EFI test harness, which I don't have.

Because of the rebuild I'm a little short on cash so taking it to a shop is not a very realistic option. I also tested the injectors and they tested fine. Was maybe the other relay bad, it came off a wrecked car that was fine before it got wrecked. Do you have any ideas on what it could be? Any advice you could give me would be very much appreciated.

Thanks,
Kevin

A. Code 16 is telling you there is a malfunction in the injector circuit. Okay, let's assume the relay and computer are good for the moment. If that is the case, the problem is with the injectors or the wiring. Lets check the injectors first.

Unplug the main injector. Red and yellow/black wires. Now measure the resistance across the injector pins. It should be between 0.6 and 1.6 ohms. If not, it's no good.

Unplug the auxiliary injector. Yellow and yellow/black wires. Now measure the resistance across the injector pins. It should be between 6 and 10 ohms. If not, it's no good.

If both injectors check out okay we have to check wires.

Connect the positive lead of your voltmeter to the yellow/black wire of the main injector connector. Turn the ignition switch on and you should have battery voltage for two seconds. If not you have a broken wire between the main injector and main relay.

Connect the positive lead of your voltmeter to the red wire of the main injector connector. Turn the ignition switch on and you should have about 10 volts for two seconds. If not you have a broken wire between the auxiliary injector and ECU connector pins A6 and A7.

Connect the positive lead of your voltmeter to the yellow/black wire of the auxiliary injector connector. Turn the ignition switch on and you should have battery voltage for two seconds. If not you have a broken wire between the yellow/black injector and main relay.

Connect the positive lead of your voltmeter to the yellow wire of the auxiliary injector connector. Turn the ignition switch on and you should have about 10 volts for two seconds. If not you have a broken wire between the auxiliary injector and ECU connector pins A1 and A3.