Need Help! RB25 running on 5 cylinders

[Lionhearted]

I feel as tho I have tried everything, so figured I would turn to the Zilvianites!

Backstory:

RB25DET in S14 Kouki. Cylinder #6 appears to not be firing. (If I pull the Coil pack or Injector clips Engine RPM etc does not change).

I have Tried: 2 ECU's, it has a brand new Wiring Specialties Harness, 2 CAS, 2 Ignitors. Ive checked for spark and its good, Compression is good all across the Board, Ive checked for Fuel its good. No noises from engine seems to run good otherwise minus sounding cammed and a slight loss in power.

The Plug that I pulled from Cylinder 6 does appear to be a little darker likes its not getting a good burn. Which I did swap to another Cylinder which is working fine.

Please help! Anything else I could be missing?

[NoFlex]

did you check timing?
I would redo all the grounds sanding them to a mirror finish just to be safe

[jr_ss]

Did you move coils to see if the issues follows? Is your injector firing? A noid light on the injector clip would tell you.

[Lionhearted]

I timed the car by ear and it runs well minus the 6th cylinder. Do you think it could be out enough to completely miss the the compression stroke? But I think then it would backfire or detonate and not run right.

I have redone every ground I could find and also added some more ground wires. From engine to bay from plenum to chassis etc.

I have not hooked up a noid light yet was going to do that soon.

Yes I have tried 4 different coil packs. Even some from my great running rb20.

[Darius]

You timed the car by ear. Holy $hit...

If you change a coil pack out and the problem doesn't change, it obviously isn't a coil pack. Pull the coils and plugs out and rest the spark plugs against the valve cover. Disconnect the fuel injector harness and crank the engine. Do all 6 plugs spark? If yes, you have an injector issue.

Remove the injector plug and test for continuity to the ECU pin. Turn the key to ON and verify that the injector is receiving power on one of the pins. If either of those are not there, it is a wiring issue. Track it down. If you have good wiring and power to the injector plug, it is a bad injector. Replace it. I even have a new stock RB25 injector I'd sell to you for cheap

[Lionhearted]

All the coilpacks are functioning. All sparking when grounded. I have hotwired the injector and it for sure works. The harness is also brand new. I'll check for continuity on the harness and see if that works to track down the wiring issue. I was going to pull the plug and crank the car and put a rag over the spark plug hole to see if the injector is firing as it should unhotwired.

Haha I didn't have a timing light and have only just gotten the car running I still plan on timing it correctly once I get the miss taken care of.

[Darius]

Do you have voltage on one of the wires on the injector plug when the ignition is ON?

[Lionhearted]

Figured it out! After plugging up a noid light found out the injector Was not firing. So traced it back to the connector where the injectors meet the main harness. One of the pins had pushed out somehow.

All fixed.

Thanks for all the help guys!

This thing is a beast now!

[Darius]

Bingo! Good work Sherlock Holmes!

[thatsoverated100]

This sounds exactly what happened to me. It ended up being the pigtail on the injector. It seemed like it was clipped on but i ended up pushing super hard and it clipped in. It doesnt sound like something that it would be but try it !!

[thatsoverated100]

Oops. Literally just read down through all the comments...... glad you got it running