So a couple months ago i got a CEL for Cylinder 1 Missfire. Started to diagnose it and replaced the ignition coil and spark plug. Still no go. Then realized there was oil residue in the well for the sparkplug so replaced my valce cover seals and sparkplug tube seals. No more oil residue but still missfiring. Recently disconected the cable completely to see if it made a difference went and drove it whith Cylinder 1 completely disconected and didnt make any difference at all. So i'm assuming im not getting either gas to the sparkplug or no spark but since i replaced the two things most common to causing no spark I'm wondering if it may be my injector. Is there a way with testing it without me having to pull off the plenum again? or is there something else it could be maybe the plug going into it? Just wondering your two cents

 

probably injectors. use injector cleaner. if that doesnt work, change injectors. check fuel pump and filter. check fuel rail too.

 

but how do you test it to see if its the injector i've tried a cleaner.

 

Interesting, there is a guy with cylinder 1 misfire issues on this thread:

http://forums.maxima.org/showthread.php?t=419750

He claims to have replaced his fuel injectors, maybe he can enlighten you on how to do that.

If you do end up replacing the fuel injectors, please take photos and post them, I'd like to see how it's done myself.

 

call around and see if any local shops test the flow of injectors, you may need to pull it out to fix this problem. Ifs not the spark, nor coil pack, very possible its the injector.

 

Ya i know how to pull off the plenum since i had to do it to replace the rear seals. Its just a ***** to do. I know you connect to multimeter to it once you have the plenum off and compare it to the others and to the haynes specs. Just curious if theres a way without pulling the plenum bc ill be upset if i go through that work and it isnt the damn injector... lol someone was saying something about checking it with a screwdriver like a s***hascope or something maybe you guys know that method?

 

Any1 know how to do this?

 

As the engine idles, listen to injector click with 's***hescope': screwdriver on injector, ear on the handle.

If it clicks, it tells that:
- ECU signal ok,
- injector wiring, coil ok,
- solenoid needle moving

 

I Had the same problem with a #4 cyl misfire about 2 weeks ago. I replaced the injector and my problem went away. The injector itself is a piece of cake to change. Pop the electrical connector off and take out the 2 phillips screws that hold the cover. The injector will pop right out. Took me about 5 min to change (of course mine was on the front of the engine)
And don't forget to bleed off the fuel presure you can pull the fuel pump fuse and run the engine until it dies.