#7 misfire help - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

57jettruck · 04-12-2018, 07:07 PM

Which grounds are you referring too? I also just swapped the entire coil pack rails to see if the code would swap sides and it didn’t.

57jettruck · 04-12-2018, 08:19 PM

Ok I checked all grounds on both heads as well as chassis ground all are good and tight and wires are good no bare wires not loose in the terminal or anything .

57jettruck · 04-12-2018, 08:35 PM

Another bit of info while using a diablo tuner to scan codes. Not mind a buddies, I was going through the list of love diagnostics and it said the ecm afr was 13.9 at idle yet my gauge is reading all over the place from 14-17.9. But if the o2 sensor was bad on that bank it would throw a code for that specific o2 sensor correct?

hammdo · 04-12-2018, 09:38 PM

Those are narrowband and usually will give a millivolt of rich or lean. You can test them but basically senses if rich/lean compared to stoichiometric (~450 mv) of the air/fuel ratio (91/93, E85 and maf ) which varies between 14.5-14.7 to 1 (depends on ethanol in the gas - up to 10% in 91/93 with some as high as 15%) and 9.5-9.8 to 1 for E85 blends.

May be a good idea to have someone with HP Tuners or EFI Live do some logging — as that may be your next course of action — if you are not able to find any apparent mechanical or electrical issues...

13.9 would be a bit rich where 17 would be lean (91/93) — if the diablo is correct in its swings - would almost indicate a vacuum leak or air entering the exhaust before the sensors somewhere...

-Don

JD555 · 04-13-2018, 08:36 AM

I had an had O2 senors go bad but it did not go out of range. I check them while running with a volt meter. The voltage value just would not swing around. Just stuck at one voltage. It did not set a code. After i changed it it went back to normal. But this was on a less sophisticated vehicle. I dont think you would get a misfire on one cyl with a bad O2 sensor.

57jettruck · 05-30-2018, 10:39 AM

Just Incase anyone is interested finally found the problem. Been on the road for a while so car was sitting but the misfire issue was bc of a dirty pin contact between the ecm and main coil pack plug.

StealingCactus · 02-24-2020, 07:15 PM

Quote:

Originally Posted by 57jettruck

Just Incase anyone is interested finally found the problem. Been on the road for a while so car was sitting but the misfire issue was bc of a dirty pin contact between the ecm and main coil pack plug.

My car is having this same exact issue.. its been driving me insane.. what did you do to fix it? what did you have to take apart? any help is appreciated

04-12-2018, 09:38 PM	#18
hammdo 'It's an experiment' Drives: [COTW 2/09/15] '11 GPI LSA SC Z/LE Join Date: May 2014 Location: Dallas TX Posts: 8,694 View My Garage	Those are narrowband and usually will give a millivolt of rich or lean. You can test them but basically senses if rich/lean compared to stoichiometric (~450 mv) of the air/fuel ratio (91/93, E85 and maf ) which varies between 14.5-14.7 to 1 (depends on ethanol in the gas - up to 10% in 91/93 with some as high as 15%) and 9.5-9.8 to 1 for E85 blends. May be a good idea to have someone with HP Tuners or EFI Live do some logging — as that may be your next course of action — if you are not able to find any apparent mechanical or electrical issues... 13.9 would be a bit rich where 17 would be lean (91/93) — if the diablo is correct in its swings - would almost indicate a vacuum leak or air entering the exhaust before the sensors somewhere... -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 Last edited by hammdo; 04-12-2018 at 09:50 PM.

04-12-2018, 07:07 PM	#15
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	Which grounds are you referring too? I also just swapped the entire coil pack rails to see if the code would swap sides and it didn’t.

04-12-2018, 08:19 PM	#16
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	Ok I checked all grounds on both heads as well as chassis ground all are good and tight and wires are good no bare wires not loose in the terminal or anything .

04-12-2018, 08:35 PM	#17
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	Another bit of info while using a diablo tuner to scan codes. Not mind a buddies, I was going through the list of love diagnostics and it said the ecm afr was 13.9 at idle yet my gauge is reading all over the place from 14-17.9. But if the o2 sensor was bad on that bank it would throw a code for that specific o2 sensor correct?

04-13-2018, 08:36 AM	#19
JD555 Drives: 2014 2SS RS, 6 sp man Join Date: Feb 2016 Location: Marlton, NJ Posts: 461	I had an had O2 senors go bad but it did not go out of range. I check them while running with a volt meter. The voltage value just would not swing around. Just stuck at one voltage. It did not set a code. After i changed it it went back to normal. But this was on a less sophisticated vehicle. I dont think you would get a misfire on one cyl with a bad O2 sensor.

05-30-2018, 10:39 AM	#20
57jettruck Drives: 2010 SS Join Date: Dec 2015 Location: Central texas Posts: 26	Just Incase anyone is interested finally found the problem. Been on the road for a while so car was sitting but the misfire issue was bc of a dirty pin contact between the ecm and main coil pack plug.