SR20DET misfiring - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

dbenavides · 10-13-2009, 07:02 AM

I just finished swapping over my SR20DET Redtop from my wrecked S14 into my new chassis. When I went to crank over the motor the first time is did not want to start. I had removed the crank angle senser so I pulled the valve cover and reset the positioning. I then tried to crank it over again and it fired but is running really rough. All my coilpacks are getting spark and my fuel lines are correct. I have Nismo 555cc injectors and the only thing I can think of is that I have the injector sequence out of order. Would this cause a misfire? The only other think I haven't check is my MAFS. Can anyone tell me where to start to look for my problem. Everything was working perfectly in my other car and all my intercooler pipes are hooked up and tight. Any help would be great!

dbenavides · 10-23-2009, 02:27 PM

Quote:

Originally Posted by dbenavides

I just finished swapping over my SR20DET Redtop from my wrecked S14 into my new chassis. When I went to crank over the motor the first time is did not want to start. I had removed the crank angle senser so I pulled the valve cover and reset the positioning. I then tried to crank it over again and it fired but is running really rough. All my coilpacks are getting spark and my fuel lines are correct. I have Nismo 555cc injectors and the only thing I can think of is that I have the injector sequence out of order. Would this cause a misfire? The only other think I haven't check is my MAFS. Can anyone tell me where to start to look for my problem. Everything was working perfectly in my other car and all my intercooler pipes are hooked up and tight. Any help would be great!

Ok I double check my coilpacks and I am getting spark. I also double checked the crank angle sensor and timing is correct. What I did find is that two injectors are not working. The injectors where working before and I am getting 12 volt constant to each injector. I believe I am not getting signal. Does anyone know where to look next if I am not getting signal? I have replaced the ignitor as well. Could this be my ECU or my crank angle sensor not working correctly?

Any help is appreciated!

P.S. The first time I went to crank over the motor after the swap I fried on of the coilpacks. One coilpack was getting 12 volts constant to a ground and it shorted out. I completely removed the wiring harness thinking I wired something incorrectly and found nothing wrong. The problem turned out to be the lower harness. I had two wires cross, a power to a ground that was causing a short. So after reinstalling everything I am able to crank over the motor and it starts but is misfiring. Could I have fried something else? Maybe the ECU? or the crank angle sensor?

dbenavides · 10-26-2009, 06:38 PM

I forgot to mention that I don't have the speed sensor and reverse light harness hooked up. Will this cause the injectors not to function? Does anyone know if the car will run without these sensors?

redsx13 · 10-29-2009, 01:21 AM

It would really help to find out what the miss actually sounds like (please try to describe), there are plenty of issues the would result in a consistant missfire, but the miss usually sounds a little different for each problem. also, is the car driveable?

10-13-2009, 07:02 AM	#1
dbenavides Leaky Injector Join Date: Feb 2007 Location: Manassas, VA Age: 43 Posts: 73 Trader Rating: (2) Feedback Score: 2 reviews	SR20DET misfiring I just finished swapping over my SR20DET Redtop from my wrecked S14 into my new chassis. When I went to crank over the motor the first time is did not want to start. I had removed the crank angle senser so I pulled the valve cover and reset the positioning. I then tried to crank it over again and it fired but is running really rough. All my coilpacks are getting spark and my fuel lines are correct. I have Nismo 555cc injectors and the only thing I can think of is that I have the injector sequence out of order. Would this cause a misfire? The only other think I haven't check is my MAFS. Can anyone tell me where to start to look for my problem. Everything was working perfectly in my other car and all my intercooler pipes are hooked up and tight. Any help would be great!

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10-26-2009, 06:38 PM	#3
dbenavides Leaky Injector Join Date: Feb 2007 Location: Manassas, VA Age: 43 Posts: 73 Trader Rating: (2) Feedback Score: 2 reviews	I forgot to mention that I don't have the speed sensor and reverse light harness hooked up. Will this cause the injectors not to function? Does anyone know if the car will run without these sensors?

10-29-2009, 01:21 AM	#4
redsx13 Zilvia Junkie Join Date: Jan 2009 Location: Agoura Hills, Ca Age: 31 Posts: 572 Trader Rating: (6) Feedback Score: 6 reviews	It would really help to find out what the miss actually sounds like (please try to describe), there are plenty of issues the would result in a consistant missfire, but the miss usually sounds a little different for each problem. also, is the car driveable?