Hey I am working on a f22b6 motor.

The car misfires and runs poorly on three cylinders.

I have spark to all four cylinders.

One injector is not spraying fuel.

I swapped in a good injector and it still did not spray.

Why would one injector power wire suddenly stop working?

I have no power to that injector, confirmed with test lights/multimeters/noid lights etc.

 

You will have to trace the wires from injector connector to ECU.You will find which circuit is affected power or drive side.Take it from there.

 

you answered your own question. one injector is not getting power thus it does not spray fuel. it would be a broken wire or a bad ecu.

 

All the injectors are driven off the same ECU output but they have separate series resistors. Unfortunately I am unable to find any information where the resistor pack is located or even what it looks like.

 

Do you know how to check injectors with a ohm meter? Check the old and new one. YouTube has several example videos.

I had one injector appear to stop firing but it turned out there was a heavy build up in the tunnel between the injector tip and the cylinder and the fuel wasn't making into the motor. My Honda sounded like a Subaru when this happened.

 

the injector resistor looks like a small aluminum colored finned box on the firewall right in front of teh driver. even if all the injectors are driven off the same ecu there are still 4 separate circuits for them. for example i had a p28 that had a bad circuit on injector #1, and no matter what car it was in that injector wold not fire.

 

The injectors are not all driven from the same output on the ECU. They are each grounded by the ECU using individual circuits. You need to find out weather it is the power side (resistor box & ignition power wire) or ground side (4 ECU pins)

I am not sure exactly where the resistor would be mounted in an Odyssey. However, it is usually mounted on the drivers side between the strut tower and the firewall on an Accord though.

Looks like this;


It's not just aluminum coloured, it is actually aluminum. It is a heat sink after all!

Using a multimeter/voltmeter it should be fairly easy to track down where the problem is. If you need more info I can send you the procedures for testing the injector, resistor box and ECU injector circuits. Just too much info to copy from the manual...............

 

He said that he swapped the known good injector and it didn't help so it would be useless to use ohm meter.

 

The simple thing to do is:take a test light and probe one wire(key on)and other.You should have light on on one of the wires(constant power).The other wire would be the driver side and the cause would be broken wire or the ECM.If you wouldn't have any light on the power side then you can trace the power side of the circuit(wires,resistor box etc.)

 

agreed. guess some people dont thoroughly read threads.

 

also agreed. all injectors have constant power. ground is what makes them fire.

 

thanks for all the help. it turned out to be a loose injector resistor box plug.

honda electrical connectors won't snap together when they are clipped onto the wire-keeping-holder. The co-worker snapped the plug together without removing it from the holding peg, and it did not 'snap' and lock all the way together.

still rather strange that 3/4 injectors were firing fine and it worked as well as it did.

thanks HT.

 

Weird.

At least you got figured out!