#7 misfire help - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

57jettruck · 04-09-2018, 05:43 PM

Hey guys been having an issue with my car lately. It’s an ls3 car with cam, headers, cai, and a 150 shot. Here’s the issue, car was running fine and I had parked it for about 2 weeks while I was out of town. I canme home and went to driving it and all the sudden it started missing but didn’t throw the cel until the following day. Code was P0357 which is #7 coil pack malf. Anyway I had new parts already so I went ahead and replaced the coil on that cylinder put new plugs in and wires. Also I read the old plugs and they all looked great. Anyway put it back together and the car ran awesome for a few short trips. Then today on a longer drive it was driving fine then boom cel came on started missfiring again. I read the codes again and it’s the same code only this time it was accompanied by a P219a which I’m assuming showed up because of the misfire. Anyway I’ve checked over the wiring and I can’t find anything of concern however I did not unwrap any loom as I didn’t see any evidence to need to do so. Also while I had the plugs out I also scoped the cylinders to look for any evidence of cracks or damage being that I am running nitrous. However I’ve only sprayed the car about 6 short bursts not even 1/4 mile on any of the pulls. Also the car doesn’t misfire constantly only under light throttle input if I put a decent load on the car it doesn’t miss at all. Any advice would be much appreciated guys thanks.

hammdo · 04-09-2018, 07:07 PM

Maybe swap the #5 injector (if swapping the coil didn’t not show anything) — see if it follows the cylinder...

Outside of that, leak down ck may be in order... maybe pull the valve cover off and see if a spring broke on #7. How many miles on the cam change? Springs go for 15-20k miles before a change may be necessary...

I’d ck injector first, then electrical, then mechanical

FYI, the 10 and 11 coil pack wires do have a heat related issue. I had to replace both of mine...

http://www.camaro5.com/forums/showpo...postcount=1662
http://www.camaro5.com/forums/showpo...postcount=1663

-Don

57jettruck · 04-10-2018, 07:10 AM

Will do thanks man, it’s just so weird the last two days I drove 70 miles into work in 50 degree temps and no misfire. Drove home in 70 degree weather and about 20 miles into the drive it starts missing.

57jettruck · 04-10-2018, 08:34 AM

Hammdo what about the air inlet temperature sensor

hammdo · 04-10-2018, 10:00 AM

Quote:

Originally Posted by 57jettruck

Hammdo what about the air inlet temperature sensor

That is in the MAF. You could clean it but, usually affects more than 1 cylinder. Get MAF cleaner. Also, you could ck to see if you have the ‘strong’ sensor since you are a 2010:

http://www.camaro5.com/forums/showthread.php?t=304720
http://www.camaro5.com/forums/showthread.php?t=291436

Make sure you have no vacuum leaks, that can also cause an issue. Has the intake manifold, CAI, or breather lines been removed lately?

-Don

57jettruck · 04-10-2018, 10:16 AM

I did check that when I first bought the car it is the strong sensor. And no nothing has been off other than flipping the throttle body for the nitrous plate and of course removing the cai tube during install.

JLGO · 04-10-2018, 10:33 AM

You need to do a leak down test.

57jettruck · 04-10-2018, 12:34 PM

Ok well my local parts store has injectors so tomorrow I will swap the injectors around and see if it follows the cylinder if it doesn’t then I will do a compression and leak down test thanks guys. I will let you guys know what happens

Pro-tuned · 04-10-2018, 06:44 PM

What type wire did you install? Did it have a heat insulator?

jcaligood · 04-10-2018, 08:27 PM

57jettruck · 04-10-2018, 08:36 PM

32819 MSD

JLGO · 04-11-2018, 08:14 AM

Quote:

Originally Posted by 57jettruck

Ok well my local parts store has injectors so tomorrow I will swap the injectors around and see if it follows the cylinder if it doesn’t then I will do a compression and leak down test thanks guys. I will let you guys know what happens

Test the compression before buying additional parts. The guess game can be costly.

57jettruck · 04-12-2018, 05:14 PM

So I’m down to wiring or ecm. Swapped the injectors and it did not follow the cylinder. I unplugged my ignition box and reconnected the factory harness and it did not change. I did compression and leak down test and they were also good leak down was 2% if that. Compression on #7 was 190

hammdo · 04-12-2018, 06:03 PM

Are the grounds on the passengers side good and tight? Verify the grounds didn’t work loose... can happen...

-Don

04-09-2018, 05:43 PM	#1
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	#7 misfire help Hey guys been having an issue with my car lately. It’s an ls3 car with cam, headers, cai, and a 150 shot. Here’s the issue, car was running fine and I had parked it for about 2 weeks while I was out of town. I canme home and went to driving it and all the sudden it started missing but didn’t throw the cel until the following day. Code was P0357 which is #7 coil pack malf. Anyway I had new parts already so I went ahead and replaced the coil on that cylinder put new plugs in and wires. Also I read the old plugs and they all looked great. Anyway put it back together and the car ran awesome for a few short trips. Then today on a longer drive it was driving fine then boom cel came on started missfiring again. I read the codes again and it’s the same code only this time it was accompanied by a P219a which I’m assuming showed up because of the misfire. Anyway I’ve checked over the wiring and I can’t find anything of concern however I did not unwrap any loom as I didn’t see any evidence to need to do so. Also while I had the plugs out I also scoped the cylinders to look for any evidence of cracks or damage being that I am running nitrous. However I’ve only sprayed the car about 6 short bursts not even 1/4 mile on any of the pulls. Also the car doesn’t misfire constantly only under light throttle input if I put a decent load on the car it doesn’t miss at all. Any advice would be much appreciated guys thanks.

04-09-2018, 07:07 PM	#2
hammdo 'It's an experiment' Drives: [COTW 2/09/15] '11 GPI LSA SC Z/LE Join Date: May 2014 Location: Dallas TX Posts: 8,690 View My Garage	Maybe swap the #5 injector (if swapping the coil didn’t not show anything) — see if it follows the cylinder... Outside of that, leak down ck may be in order... maybe pull the valve cover off and see if a spring broke on #7. How many miles on the cam change? Springs go for 15-20k miles before a change may be necessary... I’d ck injector first, then electrical, then mechanical FYI, the 10 and 11 coil pack wires do have a heat related issue. I had to replace both of mine... http://www.camaro5.com/forums/showpo...postcount=1662 http://www.camaro5.com/forums/showpo...postcount=1663 -Don __________________ 747 RWHP 794 RWTQ "Horsepower sells cars, torque wins races." - Enzo Ferrari See My Build: http://www.camaro5.com/forums/showthread.php?t=385577

04-10-2018, 06:44 PM	#9
Pro-tuned Angewendet Ingenieur Drives: 14 Camaro ZL1 Join Date: Apr 2015 Location: USA Posts: 401	What type wire did you install? Did it have a heat insulator? __________________ ———— LQ9, Iron Block, Forged internals, 408CI, Jannetty custom cam, TS short block, Whipple, Hardened Jackshaft, PRC 260, 2X3 Dynatech Full Competition, HF Cats, CAI, NW 103, Chee, ID 1300, COPO Breather, MSD, Fore Dual Pump, ultratorque, E85, dual Meth, True Trac, 3:45, 1500hp axle-shafts, DSS CF, BMR, custom Pearl/Candy paint by Jaidah.

04-12-2018, 06:03 PM	#14
hammdo 'It's an experiment' Drives: [COTW 2/09/15] '11 GPI LSA SC Z/LE Join Date: May 2014 Location: Dallas TX Posts: 8,690 View My Garage	Are the grounds on the passengers side good and tight? Verify the grounds didn’t work loose... can happen... -Don __________________ 747 RWHP 794 RWTQ "Horsepower sells cars, torque wins races." - Enzo Ferrari See My Build: http://www.camaro5.com/forums/showthread.php?t=385577

04-10-2018, 07:10 AM	#3
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	Will do thanks man, it’s just so weird the last two days I drove 70 miles into work in 50 degree temps and no misfire. Drove home in 70 degree weather and about 20 miles into the drive it starts missing.

04-10-2018, 08:34 AM	#4
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	Hammdo what about the air inlet temperature sensor

04-10-2018, 10:16 AM	#6
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	I did check that when I first bought the car it is the strong sensor. And no nothing has been off other than flipping the throttle body for the nitrous plate and of course removing the cai tube during install.

04-10-2018, 10:33 AM	#7
JLGO Drives: 2015 Camaro SS convertible L99 Join Date: Nov 2016 Location: Orlando, FL Posts: 245	You need to do a leak down test.

04-10-2018, 12:34 PM	#8
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	Ok well my local parts store has injectors so tomorrow I will swap the injectors around and see if it follows the cylinder if it doesn’t then I will do a compression and leak down test thanks guys. I will let you guys know what happens

04-10-2018, 08:27 PM	#10
jcaligood Drives: '18 SS 1LE Join Date: Jul 2016 Location: Jax, FL Posts: 405

04-10-2018, 08:36 PM	#11
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	32819 MSD

04-12-2018, 05:14 PM	#13
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	So I’m down to wiring or ecm. Swapped the injectors and it did not follow the cylinder. I unplugged my ignition box and reconnected the factory harness and it did not change. I did compression and leak down test and they were also good leak down was 2% if that. Compression on #7 was 190