Odd misfire issue on 2014 SS 1LE - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

BLK1LESS · 10-31-2015, 08:34 PM

Ls3, replaced valve stem seals recently, put fresh plugs, wires.

I have a slight miss at idle-2000RPM and it sounds like its running on 7 cylinders.

so i enabled my misfire detection back on in HPtuners (I have a SRD LS3 Cam, 233/248) It will trigger random misfire code P0300 if left enabled.

Cylinder #3 had the miss, So this is where it gets weird.

the plug was fouled, put a fresh one in, no go, the header primary for #3 was dead cold.

checked the arc on the coil to the plug wire and it's weak as hell.

I swapped coil #3 to cylinder #1 and the Arc was a LOT stronger, and the coil pack that originally came off of #1 was arcing weak and the primary was still cold.

I then swapped the entire driver side coil pack rail to the passenger side and #3 is still dead. Even tried a coil pack harness i had laying around. (put it on backwards at first LOL, sounded like gunshots)

anyways. I'm starting to think the PCM is shit or the car developed an engine harness problem out of the blue. The grounds are tight and making proper contact. I can't think of anything else guys. This car is my Daily and i pretty much need it to get to work and back.

speedygonzales · 11-03-2015, 06:19 AM

You seem to be forgetting that an engine needs fuel spark and compression to fire. Take away any one, and no fire.

I think you need to get away from spark and focus on fuel. Try swapping injectors. If that doesn't work, check the injector signal with a noid light.

Last, check compression. Correctly. With the injectors disabled and with the throttle wide open.

11-03-2015, 06:19 AM	#2
speedygonzales Drives: 99 z71, 2012 2SS Join Date: Sep 2012 Location: Smithfield, VA Posts: 205 View My Garage	You seem to be forgetting that an engine needs fuel spark and compression to fire. Take away any one, and no fire. I think you need to get away from spark and focus on fuel. Try swapping injectors. If that doesn't work, check the injector signal with a noid light. Last, check compression. Correctly. With the injectors disabled and with the throttle wide open. __________________ Fix your garage pics so we can see them

10-31-2015, 08:34 PM	#1
BLK1LESS Drives: 2014 Camaro SS 1lE Join Date: Oct 2015 Location: Houston Posts: 1	Odd misfire issue on 2014 SS 1LE Ls3, replaced valve stem seals recently, put fresh plugs, wires. I have a slight miss at idle-2000RPM and it sounds like its running on 7 cylinders. so i enabled my misfire detection back on in HPtuners (I have a SRD LS3 Cam, 233/248) It will trigger random misfire code P0300 if left enabled. Cylinder #3 had the miss, So this is where it gets weird. the plug was fouled, put a fresh one in, no go, the header primary for #3 was dead cold. checked the arc on the coil to the plug wire and it's weak as hell. I swapped coil #3 to cylinder #1 and the Arc was a LOT stronger, and the coil pack that originally came off of #1 was arcing weak and the primary was still cold. I then swapped the entire driver side coil pack rail to the passenger side and #3 is still dead. Even tried a coil pack harness i had laying around. (put it on backwards at first LOL, sounded like gunshots) anyways. I'm starting to think the PCM is shit or the car developed an engine harness problem out of the blue. The grounds are tight and making proper contact. I can't think of anything else guys. This car is my Daily and i pretty much need it to get to work and back.