rb25det misfire Help!!!

[calisfinest240]

Ok so first off the motor is an rb25det neo. when i first had it in the car it ran fine. i had to take it out because of reff issues and so i just put it in again. but now for some reason its misfiring in cyl 3 and i didn't change anything from the day i pulled it out till today. i checked the spark and theres spark coming out of the coil pack. and i also put in new spark plugs. I assume its fuel. I pulled off the injector plug for that cyl and nothing happened didn't die or drop in idle. I even swapped the injector around and its still cyl 3. I checked the volts going to the injector clip and there are no volts coming out of it. so i checked right off the ecu and nothing as well. next i decided to jump 12v to the injector wire and when i checked the clip there was 12v but when i took the clip off same thing happend idle stayed the same. so now i have no clue as to what to do next. Please any suggestions on what i should do will really help me out just let me know thanks.

[Slo_240sx]

Did it run correctly when you jumped the power wire and plugged it in? I would check the ECCS relay, and all of your input power sources. There will be a few 12v and 5v voltage wire.

The injector source votage is feed off the ECU, but it is only 1 wire and then it will branch off and feed all 6 if I remember correctly. The one you probably probed was the injector signal wire, which is a pulsed ground which is referenced off the CAS. If you jumped voltage to it there is a possibility you blew the ECU.

The correct way to check if the electrical side of your injectors are working is by using a noid light. Goto Autozone or a parts store and see if you can borrow the noid light kit, if not you will have to buy one. A Noid light comes in a kit, and directly plugs into your injector harness. When you run the car it will pulse the light showing you 12v and the injector driver pulse is good.

Good luck, if it isnt fixed by the time I come back from Afghanistan than I can come help you look at it.

[calisfinest240]

Thanks for the advice I'll have to try that in the morning. When I jumped that wire I just ran the same. The only reason I jumped it was because I checked the same wire on another injector and it read 12v so I figured if I jump it it might give it the power it needs to work.