I'm reaching out in hopes of maybe getting some helpful info to correct the issue that's before me. Nov./ 21 I installed a 6.0L with new LS3 heads in my 1st gen Camaro, LS3 intake, 92mm throttle body, Comp .565/ .568 222/224 dur 112 cam, mid length Hooker 1.75" headers. The drivers side is getting enriched to the tune of 20% at times. I thought it would be the #1 injector so I changed it out for a new one, also swapped out the coil and plug wire from #2 cylinder to see if it makes any difference. Bought a new GM iridium #1 plug 41-110 and the plug looks super clean with no carbon. WTF is going on its stumping me. Should I swap out or get a new drivers o2 sensor? The other drivers side plugs are okay wouldn't it affect the whole bank? O2 sensors are equal distance from the headers down pipe.



While the car was on the hoist I checked for any carbon deposits on the exhaust for leaks and I can't see any puffs of carbon anywhere. Running 2 wide bands Denzo #234-5117 which is the equivalent to Bosch 17014. Before I get hammered the ecm is Fitech 70050 that was purchased in 2017. The car runs fine, its just the drivers side lean condition that I want to correct on this fairly fresh engine.
Attached are the spark plug pics, 2-8 look the same except for #1. I'm coming from a SBC platform and fi is fairly new to me so if anyone can suggest where I should look into at this stage it would be much appreciated. Thanks in advance.


1-3-5-7 plugs before I changed #1, its clean.



#1 plug before I changed it



New #1 plug with about 50 miles on it and new 42lb injector from today.

 

Make sure there are NO exhaust leaks, plus ascertain both O2 sensors are working right.

 

I checked for exhaust leaks and didn't see any, I'm going to swap out the o2 sensors and see if the passenger side fuel trim follows with 20% enriching.This way I could determine if its the sensor.

If its the drivers side o2 sensor wouldn't the whole bank be getting mis reads? Why just the one cylinder plug looking clean, has me baffled? Intake leak.....gasket?

 

Make sure all injectors are flowing equally.

 

#1 looks like no spark. It’s just wet.
Do you have a scan tool?
Was this tuned?

Should be able to see misfires if it wasn’t turned off in the tune.

Possible wiring issue if you already changed the coil and wire.

 

I start stuff like that, with a infrared temp gun. I think your getting a weak spark in cylinder #1. Incomplete burn.
No spark generally give you a lean condition because you have extra oxygen in the cylinder, and the O2 doesn't read gasoline.
When you hit it with a temp gun, make sure it's up to temp first, and if you spend a couple of minutes doing it, you'll see a pattern, hit each tube in around the same spot.
What coil packs are on the car? New, used? You can try moving #1 around, also, it looks like you're pretty detail oriented, but run some boot grease if your not, and make sure the wires are snapping on.

 

The Fitech Ultimate LS 70050 harness that doesn't have a port for scan tool like the GM wiring, my friend has helped me tune things but his specialty is with Terminator and Fast. I've swapped out the #1 coil and spark plug wires to #2 and hasn't made a difference. I even changed the injector harness just in case there was a bad connection, no difference.

When I show the AFR and trims for the drivers side and pass. side it still seems to add fuel to the drivers side in the 14-2200 range. Gonna have my tuner plug in his laptop while driving and have him check things out as I'm driving, I've already sent him some log files and he mentioned things still need to be tweaked.

 

No spark generally give you a lean condition because you have extra oxygen in the cylinder, and the O2 doesn't read gasoline.
When you hit it with a temp gun, make sure it's up to temp first, and if you spend a couple of minutes doing it, you'll see a pattern, hit each tube in around the same spot.
What coil packs are on the car? New, used? You can try moving #1 around, also, it looks like you're pretty detail oriented, but run some boot grease if your not, and make sure the wires are snapping on.[/QUOTE]
exhaust


rpturbo,
Ha! funny that you mention this! my tuner gave me his infared gun to check exhaust header temp.



After taking the car out today for a drive, I used the gun when I got back home on the drivers side and here's the temperatures for 1-3-5-7 cylinders.

597- 608- 680- 667 degrees.
I guess the first 2 are closest to the fans so I believe they got cooled a bit.
I already swapped out the #1 to #2 coil and spark plug wires.
Don't get it really cause the car runs fine but when logging it seems to compensate fuel at the 14-2200 range.

Here's video of the first startup back in Nov/ 21.

 

Heres another thought.. Look at where your O2s are located.. They are back behind the bell housing of the transmission. The farther you move the O2 location from the engine, the less accurate they become. There are settings in the tune that can be changed to account for the further O2 placement.. But.. I also see the band type clamps between the engine, and your O2 sensors. By design, the exhaust band clamps are NOT 100% sealed. They will allow some exhaust to escape, and potentially some fresh air to get in and impart false O2 sensor readings. If possible... I'd remove the clamps from their current location-and weld up the exhaust such that there is no possible leak-and then move the clamps further away from the engine.. Then relocate the O2's to where the band clamps are now-closer to the engine. O2's need the HOT exhaust gasses from the motor to work correctly. Each inch away from the engine you place them allows the gasses to cool significantly thereby causing issues with O2 readings. https://forum.hptuners.com/showthrea...rs-closed-loop Good reading if you have the time. I'm NOT saying this is your issue.. But if that car was mine, these are the next steps I would try to eliminate the problem.

 

The down pipes that attach to the headers are these ones, they are recommended to match up with the mid length headers. Plus full length headers have the o2 bung at where the collector reduces down. I really don't think that my problem is there.
I'm not using a GM ecm the system is a Fitech 70050 which has been working out okay considering I purchased it back in 2017, well before Holley came out with their Terminator stuff otherwise I'd get that now.





The clamps are a overlap style that should seal, didn't use the band clamps from above. I didn't notice any carbon deposits anywhere along the exhaust.

 

After deliberating and trying to figure things out, I think I might have solved my dilemma, I didn't have a ground on the drivers side cylinder head, so I added one. Then while I was out at a Picnsave parts place for a panel cover I picked up a drivers side coil harness from another 5.3 or 4.8 engine thinking it doesn't hurt to try this for $5.00. Did these 2 things to the car and went out for a drive tonight. Had the drivers and passenger fuel trims on my handheld and things looked good, no 15-20% increases on the drivers side. Actually at idle when I first started up the car the drivers fuel trims were in the negatives possibly making adjustments to correct things from the lean #1 cylinder condition by adding fuel earlier. I'm hoping this was my issue, tomorrow I'll take out the #1 spark plug, the header will be cool by then and hopefully it has some color, fingers crossed.
Also I swapped the o2 sensors last week thinking it possibly will follow that sensor, the drivers side still enriched, so it wasn't that.

 

" I didn't notice any carbon deposits anywhere along the exhaust".
Did you take the clamps off and look at the joint for leaks?

 

It sounds like he has found his culprit with the wiring harness. Hopefully he's good to go and that's why he has not posted back. I really like it when people post back what actually fixed it as it may help others who might have similar problems, and use the search function. Really like those people..


I mean I REALLY like them..

 

It's only been 2 days since he posted.

 

Guys don't forget some of us do the 9-5 thing plus I sent the log to my tuner to verify what I was seeing and he agrees that things look better. Now he needs to tweak the tune at idle a bit and add some more fuel at the top end. I really don't know which one thing resolved things for me, either the coil harness replacement or the grounding of the drivers cylinder head, Tuner thinks its the grounding, I'm just glad things are looking better as I was thinking worse case scenario of coolant was steam cleaning the plug and I dreaded the thought of having to tear into a freshly rebuilt engine.
Pic of the #1 plug on the left after most recent drive showing signs of carbon, plug on the right is the one I replaced thinking I had a defective spark plug. Another good sign was when I put the heat gun on the #1 header pipe it registered 700 degrees. I'll post up if things change from here, tks.

 

Good deal!

 

Thanks for the follow up. Plug on the RIGHT, or lower, in the picture looks good. The TOP, or plug on the left?-looks like it has never been run in the engine.. If that plug came out of a running engine.... I would suspect it's super lean. Or not enough miles on it to get a good reading? How many miles on the TOP plug?

 

If you take a look at my very first post, pic #4 shows the new plug(now the top/left one in recent pic) and what it looked like after 50 miles on it. Looks like it hasn't even fired.
When I most recently took the car out I was more concerned with checking the drivers side fuel trim which showed a reduction in 20% adding of fuel from the lean condition that was happening. I have only put 5-10 miles at most, the main purpose of the drive was to check both fuel trims and see if they're close to the 3-5% plus or minus of one another. They are close but the drivers side is still learning and making the necessary slow adjustments. Plus my tuner needs to make some adjustments after seeing the the fuel log but that's gonna have to wait a week or so because he's just getting over Covid.
This is one time that I was happy to see carbon buildup on a spark plug. I'm sure once put some more miles on the car that the plug should hopefully have a tan hue like the others.