View Full Version : ka24e injector question

03-25-2010, 08:25 PM
alright so all of my injectors are working except for #4. I tested it with a test light and it has power. Ive swapped the injector twice and still doesnt work. I got a whole new wiring harness and it still wouldnt work. But when i swapped the injector clip with another it worked fine, i dont see how if the clip is getting power the injector doesnt work. Im thinking it might be something with the ECU but i dont know, i cant think of anything else it could be, give me some knowledge please

03-25-2010, 11:21 PM
the harness does send power to the red wire, the ecu sends a flickering ground signal to the other wire to the injector. when the injector has power and a ground it will open and allow fuel to flow through. it will have power when the key is on. the ecu will control when it gets it's ground aka "noid" signal from the ecu's hi impedence injector driver.

you have top fed 270cc hi impedence injectors on your motor stock, they're the same injectors that rb20's have and directly interchangeable.

however from what you're describing you may have a bad injector driver on your ecu vs just having a bad injector.

you could have tested continuity from the injector 3 signal wire at the ecu to the injector 3 pigtail, which would have saved you time and hassle of replacing the whole engine harness.

back to the noid signal. the best way for you to test this so you can deduce whether or not you do have a bad injector driver in your ecu (which means you'll need to replace your ecu) is to get a test light. they're cheap and easy to use.

connect the aligator clip onto the positive battery terminal, now whenever you touch a ground with the probe on your test light it will light up.

start your car, unplug the connector off of injector 3, probe the pin for the ecu ground signal (not the red wire), if your test light flickers then your ecu is working correctly and sending the noid signal to fire that injector.

hook your test light aligator clip to the negative and touch the red wire with the probe, it should light up which will double check that you have power to your injector.

then you can hook up a jumper wire to the positive terminal on the battery and a jumper wire that's grounded and touch both to your injector and when it gets power and ground you should hear it click. if it doesn't click then your injector's bad. if it does click

then test continuity from the injector plug to the ecu on the signal wire.

if you get to the last step and didn't find a problem then perhaps your cylinder 3 misfire is not due to a fuel or computer issue. then you would test for spark. then you would test for compression.

and if you didn't find a problem after that then you should take it to someone who can do the same tests correctly because the problem lies there in.

best of luck,


03-26-2010, 02:31 PM
thanks a lot man i really appreciate it ill try all that out

12-07-2014, 09:11 PM
Thread revival!!!!!!!!
What happened to be your problem??? I got no ground signal on 4th injector and i checked directly on the ecu.