So my wifes 240 is not running properly and I am stumped. The #1 injector is not firing.

Current Tech Checked:
Replaced Injector
Replaced ECU
Ran direct wire W/B from injector to ECU
Compression is 176

The only thing I can think of last is the red power wire maybe isnt working. I had a buddy use a noid light and we got nothing.

Any suggestions would be great. I need to get the car going so she can drive it.

Thanks,
Dan

 

That's the second step in the FSM for diagnosing the injectors. Here's all of them, in order.

1. Check overall function
   1. Start engine
   2. Listen to each injector, clicking noise should be heard
      • If not good go to next step
      • If good, test is done
2. Check power supply
   1. Stop engine
   2. Disconnect injector harness connector
   3. Turn ignition ON
   4. Voltage between terminal 2 and ground should be battery voltage (~12V)
      • If voltage is found go to next step
      • If not good check harness connectors for continuity
3. Check output signal circuit
   1. Turn ignition OFF
   2. Disconnect ECU
   3. Check for continuity between terminal 1 on injector harness and ECU
      • If good go to next step
      • If not good check harness for opens or shorts
4. Check injector itself
   1. Check resistance between terminals on the injector, should be 10-14 ohms
      • If good go to next step
      • If not good replace injector
5. Disconnect and reconnect all harness connectors in the circuit and retest
6. Check ECU pin terminals for damage and connection of harness connector and retest
7. The FSM was no help to you and you're screwed

What I haven't listed are the harness numbers and pins for the ECU, since they vary based on year.

 

Haha this looks to be the problem.

My buddy corrected me, the injector had power. But no operating signal. I had the pinout and ran the test wire to the correct one. Maybe I didnt have a very good connection.

The car ran fine before this happened. The symptom slowly started, it would run shakey at first start then after a second would clear up, seconds to minutes, then permanently. Ill give the signal wire one last try.

 

Although this might not work, try checking the battery terminals. I've had issues on my KA running rough and hesitating (which slowly got worse, but never as bad as an injector not firing at all) after the terminals built up a little corrosion, cleaning them off made it run smooth again.

If nothing else its a quick check/fix.

 

Will definatley try, last I remeber the terminals were covered in the acid powder.

 

Are you 100% sure the injector is not firing.

Try this:

Get a long screwdriver place it on the injector body. Listen fo the knock knock knock sound at the end of the screwdriver. That is the easiest way to tell if the injector is trying to do something. If that doesnt work then check power to the injector. I'll try to find the pin out for your ECU is you dont already have it. I have the FSM at home on my laptop.

try this ka24 pinout.

http://forums.nicoclub.com/zerothread/218674

I have a tone more stuff at home I can look up.

 

Ill try the screw driver trick. I have the pinout, 101 is the location where i ran a wire straight from the injector clip to the ecu. Only thing I can think is maybe the power wire isnt getting enough or somthing I have no clue.

PS your ECU just got shipped out today UPS, should be there tomorrow.

 

Have you actually used a multimeter at the injector connector to see if there is power to the injector? A test light (WTF is a noid light?) like I think you were talking about isn't going to tell you much of anything, you need a real diagnostic tool like a basic multimeter. You should see the same thing on all four injectors. If you don't you have a fatigued wire (likely on the power side) or a bad injector driver (ECU side) in the ECU most likely. Most of the time the injector has power on one side of the coil (an injector is a type of solenoid) and the ECU completes the circuit to ground to turn the injector on. So if you have power to the injector, it's safe to say that you have a problem on the ECU side of the fence, with wiring or the ECU itself, etc.

Someone who knows how to use a multimeter can narrow down the possibilities in a few minutes or less.

 

Got the ecu thanks. Fabric8 made a very informative post on basic troubleshooting. IIRC the injector should read only about 4.xx Volts any way. A multimeter and the FSM will be the only way to figure this out. I will be down there next week if you need any help.

 

The injector operates with 12V, but it's getting switched on and off at whatever frequency squarewave (engine RPM dependent) so you're actually reading an average of a squarewave which is why the voltage is lower than 12V. If you looked on an oscilloscope you'd see a 12V squarewave (well, sawtooth actually because of the inductance)..