2004 6.0 NV4500 Tahoe

[Dantheman1540]

Well I thought I had the AC off idle figured but today its running like shit again, wanting to die at stop lights and surging like crazy. Its strange that it runs like crap for about 30 seconds and then suddenly cleans its self up and idles great although its crazy lean like 17afr. You can see here how when it came to a stop it started jumping up and down then slowly figured its shit out and idled great for 15minutes while I was at the post office. Then I started driving and my next stop it reverted back to running like garbage and I had to give it gas to keep it from stalling. Is there some weird return to idle condition that would do this? I think I'll reset the OS/US spark settings back to stock now that I have the correct BIA.

 

[pwtr02ss]

Its happy now with the AC off, with the AC on it struggles and surges at idle still. I added 10% to the Torque model>loss>vs AC pressure table, should I adjust the Idle> proportional tables?

Take a look at my camaro file I sent. Mine doesn't like the ac on either lol

 

[randeez]

Its happy now with the AC off, with the AC on it struggles and surges at idle still. I added 10% to the Torque model>loss>vs AC pressure table, should I adjust the Idle> proportional tables?

i dunno dude. havent ever really understood the proportional and integral tables, they never seem to do what i want them to when i make changes

that seems like a lot of spark also
how are you trying to set idle or find a good idle? zero out all the adder tables, lock the entire spark table to one value ?
since you are always "in gear" the idle spark table probably does nothing

 

[Dantheman1540]

Take a look at my camaro file I sent. Mine doesn't like the ac on either lol

So I want to look at that tune and do everything opposite?

i dunno dude. havent ever really understood the proportional and integral tables, they never seem to do what i want them to when i make changes

that seems like a lot of spark also
how are you trying to set idle or find a good idle? zero out all the adder tables, lock the entire spark table to one value ?
since you are always "in gear" the idle spark table probably does nothing

I basically raised the idle to 800ACoff 850ACon thinking that should be plenty of RPM as I had it idling fine with the previous setup at 650-700. Then I just used the same idle spark of 28* in the idle cells and smoothed out around it.

For BIA I turn off all acesories and let it idle warmup from as cold as I can get it and just match the Idle desired airflow to the ECT for as many cells as I can then smooth around them.

I have never tried to zero all adder tables although I did see that in one post on the HPT forum. I also saw something about changing spark during idle to find where it makes the most vacuum but IDK how to change spark while its running.

I figured the in park tables probably did nothing but what's weird is none of the weird issues start until the truck hits zero MPH for more than one second. If its rolling at 1mph it won't do that.

 

[pwtr02ss]

So I want to look at that tune and do everything opposite?

I basically raised the idle to 800ACoff 850ACon thinking that should be plenty of RPM as I had it idling fine with the previous setup at 650-700. Then I just used the same idle spark of 28* in the idle cells and smoothed out around it.

For BIA I turn off all acesories and let it idle warmup from as cold as I can get it and just match the Idle desired airflow to the ECT for as many cells as I can then smooth around them.

I have never tried to zero all adder tables although I did see that in one post on the HPT forum. I also saw something about changing spark during idle to find where it makes the most vacuum but IDK how to change spark while its running.

I figured the in park tables probably did nothing but what's weird is none of the weird issues start until the truck hits zero MPH for more than one second. If its rolling at 1mph it won't do that.

I was hoping you'd fix it and send it back when you figure out yours

 

[pwtr02ss]

So I want to look at that tune and do everything opposite?

I basically raised the idle to 800ACoff 850ACon thinking that should be plenty of RPM as I had it idling fine with the previous setup at 650-700. Then I just used the same idle spark of 28* in the idle cells and smoothed out around it.

For BIA I turn off all acesories and let it idle warmup from as cold as I can get it and just match the Idle desired airflow to the ECT for as many cells as I can then smooth around them.

I have never tried to zero all adder tables although I did see that in one post on the HPT forum. I also saw something about changing spark during idle to find where it makes the most vacuum but IDK how to change spark while its running.

I figured the in park tables probably did nothing but what's weird is none of the weird issues start until the truck hits zero MPH for more than one second. If its rolling at 1mph it won't do that.

The only thing I can answer from this one thing is you can add spark from the special functions in the scanner, while its running. Unless I misunderstanding that little bit of the overall question.

 

[randeez]

Correct, but you take spark away, not add in the scanner

 

[pwtr02ss]

So the "up" arrow doesn't actually add anything? I messed around with that a little but only went up. I couldn't tell it was doing anything. Maybe that's why lol

 

[randeez]

The number goes up...but that's how much spark it takes away lol.

It's also a little clunky, as it I'll hit it once and if I leave Pointer hovering there it'll jump to like 5 real quick for some reason use at your own risk lol

 

[Dantheman1540]

So the "up" arrow doesn't actually add anything? I messed around with that a little but only went up. I couldn't tell it was doing anything. Maybe that's why lol

The number goes up...but that's how much spark it takes away lol.

It's also a little clunky, as it I'll hit it once and if I leave Pointer hovering there it'll jump to like 5 real quick for some reason use at your own risk lol

Oh boy another inconsistent thing to mess with lol. I just tried adding .5 to the BIA and now it just hangs everywhere. Gonna try pulling .25 out and see if that does anything.

 

[pwtr02ss]

The number goes up...but that's how much spark it takes away lol.

It's also a little clunky, as it I'll hit it once and if I leave Pointer hovering there it'll jump to like 5 real quick for some reason use at your own risk lol

Ahhh. I only hit it a couple digits up and it didn't seem like it was doing anything. This is at idle. I didn't want to keep going and mess something up

 

[pwtr02ss]

Oh boy another inconsistent thing to mess with lol. I just tried adding .5 to the BIA and now it just hangs everywhere. Gonna try pulling .25 out and see if that does anything.

My avalanche hangs the idle after it's warm. It'll eventually come down but it takes a significant amount of time. My solution was to not rev it in park lol

 

[Dantheman1540]

My avalanche hangs the idle after it's warm. It'll eventually come down but it takes a significant amount of time. My solution was to not rev it in park lol

Definitely needs a tune, it’s probably not as miserable with an auto but having to feather the throttle constantly for me is pretty awful.

 

[pwtr02ss]

Definitely needs a tune, it’s probably not as miserable with an auto but having to feather the throttle constantly for me is pretty awful.

coming soon. And yea, I don't notice it. The only thing I really notice is the dead spot somewhere around 1800-2300ish and the large gasp of air (best way I can describe it) it takes at start up. Other than that, it drives fine. Probably why Ive been dragging my feet so much

 

[Dantheman1540]

So odd, first test with the +.5 BIA had it hanging the revs everywhere however, this morning it was just stalling out everytime I'd coast to a stop. I didn't change anything but the weather is a bit cooler.

I also keep noticing these crazy readings from the MAF at idle, sometimes showing as much as 50% lean however looking at the log its only showing that lean after the idle settles down from its jumpiness. I guess I'll correct the MAF with this data this time and see what it does.

 

[Dantheman1540]

coming soon. And yea, I don't notice it. The only thing I really notice is the dead spot somewhere around 1800-2300ish and the large gasp of air (best way I can describe it) it takes at start up. Other than that, it drives fine. Probably why Ive been dragging my feet so much

That dead spot could be cured with a hit of NOS.

 

[pwtr02ss]

That dead spot could be cured with a hit of NOS.

I do have an old TNT F2 kit that was on the camaro for years

 

[Dantheman1540]

finally making some progress, basically added some air into the Idle>airflow>throttle follower>airflow table below 3.5% and it helped with the surging and stalling. Also switch to dynamic then to speed density to work on the VE table and I think the MAF might be dirty because the truck runs 150% better with the MAP active and 200% better with the MAF disabled.

I did have a very strange event tonight. I left from a light kinda hot in first gear and then really stabbed 100%WOT at 3k which in an instant had it at 6k where the engine light flashed on and the engine seemed to hit the limiter which is actually set much higher (6,500). I gently put it into second and all was fine and I did several other pulls later but keeping it below 6k. On the MAF graph im reading 10750HZ which is still 1,250 below running out of table. On the VE table it reads up to 1.05 but looking at the log the entire WOT pull is at 1.00. I think this is where the problem lies im just not sure how to fix it. DO I need a different MAP sensor? Or just a different operating system with more VE cells? I have never seen the cells actually want more than 97-99 in them but I have some upwards off 120 after correcting with my histograms.

I know some people end up needing a bigger MAF and obviously a boosted engine needs a bigger MAP sensor and OS but this isn't boosted so I'm confused.

 

[Dantheman1540]

This morning I got on it a tad and immediately got REP followed by P0068 (MAP/MAF - Throttle Position Correlation). I'm thrilled its not the standard "Your TB is a POS or your ground is bad codes". I have the MAF disabled tho so I thought this was odd, although having the MAF maybe only partially disabled would make sense.

 

[Dantheman1540]

I think I found my issue with the VE table not having enough cells. According to an HPT forum post multiplying the table by 1.25 should be plenty for a bolt on motor. Comparing my old stock 4.8 the table is more aggressive and my blown 6.0 tune has the entire table set to 4.0. So I guess I don't fully understand the table but ill do 1.25 and see wtf happens.