Fresh 5.3LS Lean at Idle

[swizcore]

Ok been trying to gather as much info as possible before creating this post in search of some help.
Go easy on me.

'02 5.3LS full rebuild. Only mods are the most mild Summit cam that doesn't require any upgraded valve train and a K&N cone filter.

The attached tune file has only been altered to raise base idle RPM and Idle airflow to get it to start and idle with no pedal.

I have ran the engine in forced open loop and forced close loop and while both are reading lean on my AEM Wideband, the engine sounds better and reads less lean when in closed loop.

Looking for a few answers:
1. Even though the tune is set up to force closed loop, scanner channel shows Closed Loop Active - No. Why?

2. Scanner Channel has always shown "Fuel System - OL Not Ready"... Not sure why?

3. I want to begin dialing in the MAF but I really want to get this lean idle reading dialed in before I attempt any throttle tuning. Initially I assumed the lean readings were bad because my nose tells me it's definitely not lean. I have been around the intake with carb cleaner, no surges and also blew into the exhaust and found a minor leak at the header gasket which I have since sealed. I feel like my next step should be verifying my injectors are fine, is there a scanner channel I can setup to verify this?

4. Assuming my injectors are all good and it is indeed a correctly reading lean condition, where should I start to dial in the AFR at idle before moving on to MAF tuning?

Thanks

Swizcore_Base_GoatRopeGarage_VE_ForcedCloseLoop_324_201010.hpt
Swizcore_Base_GoatRopeGarage_VE_ForcedCloseLoop_324_201010.hpl

Video clip of AER Gauge and Scanner during scan:
https://www.youtube.com/watch?v=DMMEBTWoVjI

[B52bombardier1]

What do your Long and Short Term Fuel Trims indicate?

Rick

[5FDP]

The o2 sensors are not even alive in that data log. You have them both stuck at 450mv meaning they are not even plugged in or have zero power going to them.

You can not force closed loop and have anything function if the o2 sensors don't even work because o2 sensors are required for closed loop fuel control.


You won't have enough fuel injector on those stock 21lb/hr injectors. Those are the smallest injectors offered on those engines, you need 25lb/hr or 31-33lb/hr injectors at a minimum if you ask me.


I understand you are new to tune here and the tune shows things that aren't matching up. The MAF fail high is to 0hz but the MAF sensor trouble codes are not set to MIL on first error if you were speed density tuning. The dynamic airflow high rpm disable for the MAF/VE is set to 10,000rpm, so it won't use the MAF but the MAF is also not failed correctly yet. And with those settings currently you can't tune the MAF or the VE as it won't know what you are trying to do.

I guess the video's you are following to do tuning are messing you up because it's all kinda backwards.

[swizcore]

The o2 sensors are not even alive in that data log. You have them both stuck at 450mv meaning they are not even plugged in or have zero power going to them.

You can not force closed loop and have anything function if the o2 sensors don't even work because o2 sensors are required for closed loop fuel control.

This has also been curious to me, of all the scans I've run during this, both o2 readings have remained not stagnant (they do fluctuate nearly imperceptibly) but not near what looks like a legitimate reading. I have verified the 4-wire connector at each o2 reads: pink 12v, two wires 480mv and black ground. This is with key on but not running and sensors at ambient temp. Would this indicate that merely the sensors themselves are bad? They are new but Ebay items.

You won't have enough fuel injector on those stock 21lb/hr injectors. Those are the smallest injectors offered on those engines, you need 25lb/hr or 31-33lb/hr injectors at a minimum if you ask me.

Thank you, I'll make a move on these once I get some progress on the o2 issue.

I understand you are new to tune here and the tune shows things that aren't matching up. The MAF fail high is to 0hz but the MAF sensor trouble codes are not set to MIL on first error if you were speed density tuning. The dynamic airflow high rpm disable for the MAF/VE is set to 10,000rpm, so it won't use the MAF but the MAF is also not failed correctly yet. And with those settings currently you can't tune the MAF or the VE as it won't know what you are trying to do.

I guess the video's you are following to do tuning are messing you up because it's all kinda backwards.

I totally agree with you here. I've been doing so much research lately, I'm a bit overwhelmed but I am starting to grasp the principles.

I get the sense my next move should be simply starting with the stock tune with the base idle and airflow bumped to achieve idle without pedal but forget about the forced close or open loop until I diagnose this o2 issue.

Any advice on where to start on that? I hate to burden but I'm committed to understanding and resolving most every problem I encounter.

Thanks for the response.

[swizcore]

I verified my o2 Sensors are heating but I'm confused by how the Scanner is showing their presence.
My PCM pinout states the wires I utilized for the o2 sensors are for Bank 1 Sensor 1 and Bank 2 Sensor 1 but the below image is not showing that.

Screen Shot 2020-10-12 at 6.39.00 PM.png

Also getting this under Diagnostics.

Screen Shot 2020-10-12 at 6.31.16 PM.png

Clearly something is awry since Scanner shows that it see's o2 sensors, they are heating but also creating DTC's. I've read that LS1's have two possible o2 sensors with a difference in grounding method which can determine whether the PCM jives with it. Could having the wrong sensor cause these conditions?

[5FDP]

I'd blame the garbage ebay sensor. AC delco or Denso sensors only on GM car/trucks.

The log has the correct channels for the o2 sensor voltages but they show the o2 sensors not working.

[swizcore]

I'd blame the garbage ebay sensor. AC delco or Denso sensors only on GM car/trucks.

The log has the correct channels for the o2 sensor voltages but they show the o2 sensors not working.

Gotcha. I have Delco sensors arriving tomorrow. Assuming they clear up that issue, would these be too much injector for my setup?

https://www.lsxceleration.com/delphi...rs-12613412-8/

During rebuild I went through the injectors and rails, they were quite nasty so I wouldn?t be surest all if they are at minimum part of the problem.

[5FDP]

No, those would be fine but they are very big for what you have. All the data is available for GM injectors, you just need to find a tune with that data and use a LS1 to LS3 style spreadsheet to make the data work in the tune.

Or find injectors from a flex fuel suburban/tahoe as those are 33lb/hr as those are more than enough for a modded 5.3.

[swizcore]

Ok appreciate that info.

I got a little progress after work tonight and pulled the fuel rail and injectors to test spray. I have two completely dead injectors. 🤦🏻*♂️

I have another complete fuel rail that im sure I can find two good injectors out of, so with a bit of luck on those o2?s maybe I can actually start to tune.

... and ask some slightly less dumb questions. (No promises).

Thanks for keeping my brain engaged!

[swizcore]

o2's arrived today and they had the additional ground wire to the body of the sensor unlike the cheap eBay sensors, which I assumed was good . Wire colors were different than eBay colors which I figured was irrelevant.

After installing them:
Screen Shot 2020-10-14 at 9.41.30 PM.png

Is B1S1 saying "Ready - No" out of the ordinary? Heat related? This is simply with key-on. I can't fire it till the two new injectors show up Friday.

This screen is still showing incomplete even after clearing DTC's:
Screen Shot 2020-10-14 at 9.56.08 PM.png

[swizcore]

Injectors arrived today and I'm finally running stoich (imagine that, 2 cylinders of no fuel = Lean ) and ready to start tuning. Thank you 5FDP.