4.3 Turbo tuning help

I am tuning a 2000 4.3 turbo with marine intake and stock bottom end. I am using the 411 PCM. My problem is, when i go and start the truck cold it seems to run good, the AFR error table is in check. I can drive and log, all is well. Once I park, sit and idle, turn off the truck and immediately start it back up, now everything is lean. I'm lost. I will post the tune and the 2) logs 1) good 1) lean.

Also, Once I think I have a good tune, where should i post my tune to get some experienced eyes on it. I'm uncertain on a few things.

My first recommendation is to plug the narrowband O2's back in then tune CL. Use wideband for PE.

Undo your changes to the OL tables. Check the EGR airflow and spark tables. Blend Boost Enrichment into PE EQ Ratio. Re-enable Complex Temperature Model.

You're running 27lb injectors with a turbo?

Take that back. My first recommendation is to set Engine Diag>Airflow>MAF Frequency Fail High to 0Hz.

I was planning on re installing the narrowband O2's once I had the VE and MAF tuned in, right now I've only made it to the VE table.

I have deleted the EGR, I believe I have it disabled in Engine>Exhaust>disable/enable>200mph. If I have it deleted, do I need to zero out EGR airflow and spark?

The MAF frequency Fail was set to 12,000, that was a ugh ooh, zero better? I'm going to have to start using a mouse, moving my cursor around with the mouse pad is going to cause me issues i see.

I'm running a small T3 turbo, I've seen about 9 psi and still able to see 10.00 afr.

I will change the MAF fail to 0, blend the Enrichment tables, shouldn't I be able to tune the VE in Speed Density without narrowband o2's? I will enable Complex Temperature Model, It must have been Disabled from the factory.

I appreciate your help.

My IAT sensor is still in the stock location, the breather tube before the throttle body. Do I need to relocate it into the intake manifold?

Yes those need zeroed out.

Moving the IAT to the manifold is something to do if the current location is upstream of the turbo.

Tune VE with narrowbands in CL. When PE engages then pay attention to the wideband. Don't tune with the wideband then enable CL afterward.

I zeroed out the EGR airflow and spark, that helped, not as lean now, but still bouncing between 15.5 to 17.0.before I shut it off, it was 14.0.
It's still seems to be getting air added once I make a drive and come home shut it off and start it back up. I let it run a bit to see if it will work itself back to a decent afr, but it never does.
I tried enabling the Cylinder Charge Temperature, it pegged out lean.

Would Hotsoak Enrichment have anything to do with it?

Transient Fueling?

Are you still running factory injectors? That's not the stock flow rate. Wouldn't hurt to look at them and read off the part number.

Heatsoak enrichment may help.

Have you turned CL back on yet?

These are the factory marine intake injectors, bought the intake complete. They are supposed to be 24# injectors, @43 psi, checking other information on these marine intake installs, it worked out to be 27.7 @ 58 psi.

Does VE correction have anything to do with a re start, or does it only affect Steady State?

I have not gone back to CL yet, I feel if I don't fix this problem now, it'll be there in CL also. It runs great, only lean after re start. Come out a few hours later runs great again.

I was thinking going back to CL is going to add in more tables, adders, ect.., and if the problem is still there, more to sift through.

After i returned from my drive after the EGR zeroing, I re started and I thought it was fixed, acted normal. Turned it off restarted again to verify, and it was lean.

do I need to post any different logs or anything?

I am asking for help, and you have mentioned CL a couple of times, would going back to CL be my best place to start. I only have two bungs welded in my down pipe, I'll need to add another somewhere for the wideband or second narrowband.

I do appreciate your time, and help.

Quote:

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Originally Posted by Pcaudell

I am asking for help, and you have mentioned CL a couple of times, would going back to CL be my best place to start. I only have two bungs welded in my down pipe, I'll need to add another somewhere for the wideband or second narrowband.

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Both narrowbands plus a wideband.

I have the 2) narrowbands and the wideband installed, and closed loop enabled. I have also attached a drive log.

what do you think?Attachment 141718Attachment 141719

Nice glad to see both. However, you didn't set MAF Fail Frequency High to 0Hz.

Here's a few suggestions. Open it and press CTRL+L to see what I did.

Right, I put it in closed loop. Looking at your changes, that would be set up for VE tuning with STFT, being that the LTFT are disabled. Is that where I need to start, then move to the MAF and tune the same way?

Changing the Rich/Lean vs Airflow to .451 I'm thinking puts Stoich in the middle range of the sensors?

I did notice I haven't set up my STFT and LTFT histograms to match my 2 bar VE table, need to do that.

Also need to add injector duty cycle to my channels list.
I noticed at 8:25.9 in the log file it went into OL FAULT. Looks like it had something to do with the Narrowbands.

Yes tune VE first. Don't bother with MAF at all for this build.

Middle of the range. Stock settings bias it toward rich. The further away from 451 the more inaccurate the sensor reads.

OL Fault happens when the closed loop can't maintain control. I've seen this happen with incorrect injector data, but there are other causes.

In order to get injector duty cycle to log you have to log injector pulsewidth for B1 and B2.