View Full Version : Fuel Injector not firing causes no spark in coil?

02-06-2003, 02:34 AM
I am having a problem with my SR (it's not firing in cylinder 1). I was about to buy a new igniter (these things are expensive) but figured I should pull the injector plug off of cylinder 1 to see what will happen. I found out that nothing happens. When I pull the injector plugs off of cylinder 2, 3 and 4, the revs would drop. Only cylinder one does not change. I remember reading a post stating that if the fuel injector is not firing then the ecu will not send spark to that cylinder. Does the fuel injectors run off some kind of controller/device in which I can check for problems (only ECU I'm assuming)? ALso before this all happened, I found our that my fuel pump fuse had blown. After replacing the fuse, it is still running on 3 cylinders. Any ideas that can help me out guys?

02-06-2003, 02:36 AM
You can try swapping with a different injector in the rail and see if it's the injector or the ECU controlling the injector.

02-06-2003, 05:09 AM
</font><blockquote><font class="small[/img]In reply to:</font><hr />
Any ideas that can help me out guys?

if the fuel pump fuse blows, you have no fuel, well, not pressurized fuel, so your motor will not fire or if this happened while you were driving, the motor would stall, or lean out big time.

why did the fuse blow? if you haven't changed any wiring, will it blow again in future?

no one suggested to check for d.t.c., wow, it has been a while since i last typed those three letters.
there maybe a few codes stored, 21, 11?

if you flip through the pages of troubleshooting section in the s14 silvia fsm, there should be explanations on how to check for ground and power in your injector circuit; right after that is a bit on ignition circuit.
mine shows all this stuff in the ef/ec chapter, engine fuel and emission control, in japanese.
english copy is available, but i don't have one; and if you don't have one, you should get one.
you want answers, you have to flip pages. electrical troubleshooting is a tough one to handle on www.
you'd get better results by taking care of the diagnosis on your own. fsm, tester and enthusiasm.

02-06-2003, 01:22 PM
I swapped out the injector with an extra one that I had lying around. Same results. I also used a multimeter to measure if there was any current going through the injector and there is. Hopefully I can find the problem without purchasing a new igniter. I'll try to get some ecu codes today when I have time.

02-06-2003, 02:33 PM
You will most probably get #55 ecu code....I rarely see nissan ECU giving code. (I personaly think that you could explode de engine and it would still give you 55#)

I'm sure that your injector is firring, there is no shuch a thing as "if there is no spark the nissan computer doesn't send fuel"

Is that sparkplug new? are you sure it's not flooded ?

I would suggest trying to connect the signal for the cylinder #1 going into the Ingitor chip to the pin for another cylinder and then connect the output pin to the cylinder # 1 coil. (I'm not sure it's clear, just try to use another transistor of the ignitor chip for the cylinder #1)

(an ignitor chip for SR is made of 4 transistors)

This will let you know if the ignitor chip is good or not!

02-07-2003, 03:34 AM
</font><blockquote><font class="small[/img]In reply to:</font><hr />
Hopefully I can find the problem without purchasing a new igniter. I'll try to get some ecu codes today when I have time.

you and many others have it backwards.
you better hope that your problem doesn't remain after you purchase a new expensive igniter.

you should check your ecu for codes, carry out a full diagnosis on your electricals before you spend a dime, change a component, jiggle with a coupler, pick up a wrench, or hit up the internet.

we don't have a consult like the mechanics at nissan, but common sense tells me, that buying a new igniter or any other components isn't the first step to figuring out your problem.

02-07-2003, 04:16 AM
so well said srfiveten... damn.. preach on brothah