need help idle tuning my gen4 e38

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03-02-2022
Z107

4 Attachment(s)

need help idle tuning my gen4 e38

ive been trying to tune my idle on my own for a while but i could never get it right. So i used this guide here to help me out https://forum.hptuners.com/showthrea...e-tuning-guide

Im having issues with certain areas, and its more or less a knowledge issue. Right now im still on the first step trying to find out where my spark should be.
ive done all the steps to make the tables reference the right areas. Heres a few logs i got.Attachment 117957 Attachment 117958

ive set spark to 24 to start. not sure what i should be looking for on vcm scanner or how to test if ive got the correct spark. any help on this matter is appreciated.

heres my tune and specs.Attachment 117959

2010 camaro ss e38 ecu cammed, plan on tuning for e85. cam specs 229 242. zl1 fuel pump.

for reference heres my base tune with added 900rpm idle.Attachment 117960
03-02-2022
kevin87turbot

Quote:

Originally Posted by Z107

ive been trying to tune my idle on my own for a while but i could never get it right. So i used this guide here to help me out https://forum.hptuners.com/showthrea...e-tuning-guide

Im having issues with certain areas, and its more or less a knowledge issue. Right now im still on the first step trying to find out where my spark should be.
ive done all the steps to make the tables reference the right areas. Heres a few logs i got.Attachment 117957 Attachment 117958

ive set spark to 24 to start. not sure what i should be looking for on vcm scanner or how to test if ive got the correct spark. any help on this matter is appreciated.

heres my tune and specs.Attachment 117959

2010 camaro ss e38 ecu cammed, plan on tuning for e85. cam specs 229 242. zl1 fuel pump.

for reference heres my base tune with added 900rpm idle.Attachment 117960

Here's what needs to be done.

1. Calibrate your fuel tables. It's too lean at an idle. It just needs more fuel. Start with the MAF curve.
2. Change your Dynamic High RPM Disable to 300 and Re-enable to 200 to start with, then you can add fuel to your MAF curve.
3. Change your High Octane table back to stock. It'll be much better as far as driveability. Copy the High Octane table over to the Low Octane table, and just subtract 5 degrees from the entire table from 1200 rpm-up and 0.40 gms and up.
4. With this cam and a manual transmission, you might even increase the idle rpm to 950.
5. After doing all of this, you can then dial in your VVE tables.
03-03-2022
Z107

I am by no means good at tuning so ive got very limited knowledge. So when you say add some fuel to the maf curve should i just multiply the entire curve by 5% or only the idle area. Also what other tables are there that i can manipulate regarding fuel? All i have in memory are maf and vve.

In regards to vve, i tried adding some fuel into the lower end, about 5% but the st+lt values didnt really change. Is there something im not doing correctly or is my fuel system not up to par for this cam?

Also i should note that my idle is varying quite rapidly according to my wideband from 14.3 to 15.6.
It just teeters between them sometimes staying on course of 14.7 sometimes dipping over into 16. All of this data together is just really confusing to me and im sure theres one explanation that solves all my questions i just dont know what that is.
03-04-2022
Gustavo

1 Attachment(s)

Here you go dear

Attachment 118007
03-15-2022
Z107

Quote:

Originally Posted by Gustavo

Here you go dear

Attachment 118007

I tried this under some different circumstances using a flex fuel tune i have and got some pleasing values now. My idle is more stable and predictable, i.e. its still running lean but the stft+ltft values are the same every time instead of fluctuating at idle. Im going to try to mess with my vve when i get off today as well.

One concern has arisen however. My idle on cold start is incredibly rich, which im assuming is because long term fuel trims havent kicked in yet. If theres any way to prevent that or at least run it less rich id love an explanation as to how so i can learn a bit from it.
03-16-2022
Gustavo

Your EQ ratios are fluctuating spikes, try adjusting to have it in a linear manner. Moreover, the flex fuel sensor is turned off in the tune, how did you run the ethanol ? Did you enable it before writing the file ?
03-16-2022
Z107

Quote:

Originally Posted by Gustavo

Your EQ ratios are fluctuating spikes, try adjusting to have it in a linear manner. Moreover, the flex fuel sensor is turned off in the tune, how did you run the ethanol ? Did you enable it before writing the file ?

I have an old tune i used to have for flex fuel when i had stock cam. I will post log and tune here soon when i get my laptop. I will try to get a cold start to warm as well.
03-16-2022
[email protected]

most chevys that ive seen start off at 18 degrees as a base for idle spark advance
03-17-2022
Z107

2 Attachment(s)

Quote:

Originally Posted by Gustavo

Your EQ ratios are fluctuating spikes, try adjusting to have it in a linear manner. Moreover, the flex fuel sensor is turned off in the tune, how did you run the ethanol ? Did you enable it before writing the file ?

Attachment 118485 Attachment 118486
03-18-2022
kevin87turbot

Quote:

Originally Posted by Z107

Attachment 118485 Attachment 118486

The VVE tables still need to be dialed in. The Manifold switched closed and open tables need to match as well.

For now, change the Dynamic High RPM Disable and Re-enable to 300 and 200 respectively.
That will allow you to dial in the MAF table.
03-19-2022
Z107

Quote:

Originally Posted by kevin87turbot

The VVE tables still need to be dialed in. The Manifold switched closed and open tables need to match as well.

For now, change the Dynamic High RPM Disable and Re-enable to 300 and 200 respectively.
That will allow you to dial in the MAF table.

I heard somewhere that you can dial both the vve and maf in at the same time on gen 4 ecu's (e38 and up) using a math feature in scanner? talked about not having to shut off open loop. would this be a better way of going about dialing in the maf?
03-30-2022
Z107

Quote:

Originally Posted by kevin87turbot

The VVE tables still need to be dialed in. The Manifold switched closed and open tables need to match as well.

For now, change the Dynamic High RPM Disable and Re-enable to 300 and 200 respectively.
That will allow you to dial in the MAF table.

How would you recommend logging maf error since i dont have a wideband that can connect to hptuners? My aem did not come with the obd port, only extra wires for things like power and logging on the old system. I have the newest one btw i think its mpvi2 if im correct.