cyl 3 & 4 are lean

s346k · 05-01-2021, 12:58 PM

2018 ss 1LE. pulled the plugs today. bolt ons & ethanol since april 2020, about 10k miles of (hard) use. i noticed cyl 3 & 4 were lean(er) than the others. i think i have enabled the correct pids in hpt to log timing & fuel / cylinder, will find that out later.

cyl 3 plug has about 4k miles on it. still looks brand new and very lean. noticed that the timing marks on the other 7 are higher up on the strap than 3, also. the other 7 plugs have 10k miles on them. pic is taken as youre standing in front of the car, bottom right 1, bottom left 2. also found a use for the factory paper filter.

ideas? car has a mamo ported msd intake manifold, wondering if there is a contributor in there somewhere. compression on #3 was ~270 lb. checked cold, car has been sitting since monday morning. no plugs so it cranked over ssslloowww.

sigh. pic needs to go 90* clockwise.

edit: 28.5*/.88 on ethanol

Trochoidal · 05-01-2021, 03:07 PM

Rotated 90°
I’m in on seeing what your log shows.
Makes me wonder if you have a coil issue on #3.

s346k · 05-01-2021, 03:47 PM

Quote:

Originally Posted by Trochoidal

Rotated 90°
I’m in on seeing what your log shows.
Makes me wonder if you have a coil issue on #3.

thx for rotating the pic. and yeah idk what's going on in 3. never had an issue with anything (that im not responsible for), car has ran perfect since day 1.

Trochoidal · 05-01-2021, 04:11 PM

Quote:

Originally Posted by s346k

thx for rotating the pic. and yeah idk what's going on in 3. never had an issue with anything (that im not responsible for), car has ran perfect since day 1.

You’re welcome. Same here. If something goes wrong for me it’s usually self-inflicted.

Granted I’m on a phone, but I singled out 3 vs 4 because it does looks cold and the timing mark on the strap looks like it’s further around.

Am I seeing it right that your strap marks look like they’re right where they should be on the other 7 plugs (including #4)?

KingLT1 · 05-01-2021, 06:23 PM

Possible injector issue?

6spdhyperblue · 05-01-2021, 06:26 PM

Did u use new wires?

Any chevron Techron?

s346k · 05-01-2021, 06:51 PM

Quote:

Originally Posted by KingLT1

Possible injector issue?

thats what i was thinking. gonna do some logging and hopefully learn something.

Quote:

Originally Posted by 6spdhyperblue

Did u use new wires?

Any chevron Techron?

yes it got new wires with the plugs. no chevron. exclusively ethanol except over winter.

6spdhyperblue · 05-01-2021, 07:23 PM

Me too on e. I started running chevron techron injector cleaner once a year, their spec sheet is saying good with e85. Idk.

s346k · 05-01-2021, 10:41 PM

well. best i can tell is it's fuel delivery. car will pop (lean im assuming) about every 3rd pull, but hpt isn't picking up a misfire. im confident its #3. stft are lean everywhere on that side now. pretty consistent wot around 5k rpm, especially after a shift.

Trochoidal · 05-01-2021, 11:42 PM

Quote:

Originally Posted by s346k

well. best i can tell is it's fuel delivery. car will pop (lean im assuming) about every 3rd pull, but hpt isn't picking up a misfire. im confident its #3. stft are lean everywhere on that side now. pretty consistent wot around 5k rpm, especially after a shift.

If you have an IR thermometer, check#3 primary to see how it compares. I’d even see what #4 and the other look like too.

s346k · 05-02-2021, 12:04 AM

yeah i got one but it's not here. it is among the items im getting tomorrow.

s346k · 05-03-2021, 10:06 AM

update: got fuel lines, (used) injectors, plugs & wires on the way. going to pull the injector in question and send it with the used ones to be checked, cleaned etc. want to see what's up with the old one and simply verify the others are good. fun stuff. all signs point to an injector issue so we will find out in the next couple weeks. now i gotta figure out how to depressurize this fuel system.

avalonandl · 05-03-2021, 10:23 AM

I doubt its plugs or wires.

EDIT: Does the car idle rough? #3 looks like itsnot even firing....

s346k · 05-03-2021, 10:47 AM

car idles and drives perfectly. i was only tipped off to an issue when the car popped at high rpm (has been mechanically flawless since new). the injector is being told to fire the exact same as the other ones. timing in that cyl is almost identical to the rest (variance of <.3*).

it needs wires, i have 6 black older ones and 2 red -even older than those- ones. i'm going to start over fresh with plugs simply to eliminate any variables should i still have an issue.

05-01-2021, 12:58 PM	#1
s346k Drives: like an old lady Join Date: Jun 2012 Location: indiana Posts: 2,395	cyl 3 & 4 are lean 2018 ss 1LE. pulled the plugs today. bolt ons & ethanol since april 2020, about 10k miles of (hard) use. i noticed cyl 3 & 4 were lean(er) than the others. i think i have enabled the correct pids in hpt to log timing & fuel / cylinder, will find that out later. cyl 3 plug has about 4k miles on it. still looks brand new and very lean. noticed that the timing marks on the other 7 are higher up on the strap than 3, also. the other 7 plugs have 10k miles on them. pic is taken as youre standing in front of the car, bottom right 1, bottom left 2. also found a use for the factory paper filter. ideas? car has a mamo ported msd intake manifold, wondering if there is a contributor in there somewhere. compression on #3 was ~270 lb. checked cold, car has been sitting since monday morning. no plugs so it cranked over ssslloowww. sigh. pic needs to go 90* clockwise. edit: 28.5/.88 on ethanol Attached Images __________________ 2016+ camaro: everyone’s first car Last edited by s346k; 05-01-2021 at 04:08 PM.*

05-01-2021, 03:07 PM	#2
Trochoidal Drives: 2017 Camaro 2SS A8 Join Date: May 2019 Location: USA Posts: 1,656	Rotated 90° I’m in on seeing what your log shows. Makes me wonder if you have a coil issue on #3. Attached Images __________________ Roto-Fab w/sound tube delete, Katech ported TB, Pray IM, Velossa, DD side markers, DSX FF, UPR Catch can, Halo brace, My custom vent gauge pod Originally Posted by arpad_m - “Aww, yet another oil thread with almost the same question in the OP“

05-01-2021, 06:23 PM	#5
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,796	Possible injector issue? __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

05-01-2021, 06:26 PM	#6
6spdhyperblue Drives: 6th gen Join Date: Aug 2013 Location: US Posts: 3,675	Did u use new wires? Any chevron Techron? __________________ ‘22 2SS 1LE M6 Summit White - RF, Flexfuel, LT2 intake, 95mm tb, ATI udp, VT ramair, full 28” dragpack - 11.68@122 ‘16 1SS M6 LT2 intake + boltons on DR 11.0@126+ (Sold)

05-01-2021, 07:23 PM	#8
6spdhyperblue Drives: 6th gen Join Date: Aug 2013 Location: US Posts: 3,675	Me too on e. I started running chevron techron injector cleaner once a year, their spec sheet is saying good with e85. Idk. __________________ ‘22 2SS 1LE M6 Summit White - RF, Flexfuel, LT2 intake, 95mm tb, ATI udp, VT ramair, full 28” dragpack - 11.68@122 ‘16 1SS M6 LT2 intake + boltons on DR 11.0@126+ (Sold)

05-01-2021, 10:41 PM	#9
s346k Drives: like an old lady Join Date: Jun 2012 Location: indiana Posts: 2,395	well. best i can tell is it's fuel delivery. car will pop (lean im assuming) about every 3rd pull, but hpt isn't picking up a misfire. im confident its #3. stft are lean everywhere on that side now. pretty consistent wot around 5k rpm, especially after a shift. __________________ 2016+ camaro: everyone’s first car

05-02-2021, 12:04 AM	#11
s346k Drives: like an old lady Join Date: Jun 2012 Location: indiana Posts: 2,395	yeah i got one but it's not here. it is among the items im getting tomorrow. __________________ 2016+ camaro: everyone’s first car

05-03-2021, 10:06 AM	#12
s346k Drives: like an old lady Join Date: Jun 2012 Location: indiana Posts: 2,395	update: got fuel lines, (used) injectors, plugs & wires on the way. going to pull the injector in question and send it with the used ones to be checked, cleaned etc. want to see what's up with the old one and simply verify the others are good. fun stuff. all signs point to an injector issue so we will find out in the next couple weeks. now i gotta figure out how to depressurize this fuel system. __________________ 2016+ camaro: everyone’s first car

05-03-2021, 10:23 AM	#13
avalonandl Drives: 2019 ZL-1 Join Date: Feb 2009 Location: Troy, MI & Naples, FL Posts: 2,019	I doubt its plugs or wires. EDIT: Does the car idle rough? #3 looks like itsnot even firing.... __________________ 2019 ZL-1 Acquired 4/23/21 at 6300 miles. Riverside Blue, A10, PDR. Traded in 2017 2SS with 6M and 32k miles. Continental Extreme Contact Sports. Now has 10,000 miles... 2012 Yukon XL Denali w/ 6.2 AWD

05-03-2021, 10:47 AM	#14
s346k Drives: like an old lady Join Date: Jun 2012 Location: indiana Posts: 2,395	car idles and drives perfectly. i was only tipped off to an issue when the car popped at high rpm (has been mechanically flawless since new). the injector is being told to fire the exact same as the other ones. timing in that cyl is almost identical to the rest (variance of <.3*). it needs wires, i have 6 black older ones and 2 red -even older than those- ones. i'm going to start over fresh with plugs simply to eliminate any variables should i still have an issue. __________________ 2016+ camaro: everyone’s first car

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