Hey guys, I got the cam in last weekend. Everything seems great mechanically. Now I'm working on the tune. I've got the VE table dialed in and am starting to look at the MAF calibration.

My biggest problem is with the idle. I've increased the idle air number across the board and raised the idle speed to get it to idle but I'm no expert in tuning the idle. It idles pretty good when it's warm but it won't hardly idle on a cold start up. Sometime it even dies.

Can any of you give me some pointers as to what I need to do? What parameters to adjust and how to log it to determine what needs to be done? If anyone has a similar cam and HPTuners would you share your tune for me to compare to?

I am supercharged but I don't think that much of a factor at idle. Correct?

Mods in sig,

TIA

 

In EFILive, Startup Airflow Friction is the table you'll want to add to (probably start with a couple g/sec). That air is decayed out over a set time after startup. Also, you could add to the startup rpm offset table which adds your input rpms to the desired idle rpm. So if you added 150 rpms and the desire was 800, it should bust off at aout 950 and then taper back down to the desired. Hope that helps some!

Ryan

 

Load up this config and tune your RAF also. Helped mine alot.

Save the file as Idle Airflow.cfg
Load it in the scanner
Start the truck cold and start logging with this config immediately
Take the numbers from the histogram and paste into your RAF table.

 

Thanks Roger. I knew it was simple but didn't know how to set it up but every time that I try to download it or save it, all I get is a .txt file. If I open it, I get a bunch of mumbo jumbo.

Any pointers or do you think it will go as a email attachment? I'll PM you my email address if you don't mind trying that.

 

You should be able to save the file somewhere local on your machine. Then rename it with a .cfg extension.

 

That's where I screwed up. It was saving as a .txt. I didn't think about just renaming it.

I may make a first run at it tonight after the truck has sat for 3 or 4 hours but I'll definately get out early in the morning and log it.

 

I just logged it. Does it seem possible that I could have got these numbers?

89deg ............................ 177deg

34.62 36.85 23.96 11.17 10.46


That is WAY high compared to my stock table, especially in the lower ECT temps.

 

I got even crazier numbers this morning. Every cell from 46deg to 111deg shows "40" in it. It can NOT have the same desired airflow through all 4 cells.

 

hmmm. Yeah those are way high and I'd bet it caps at 40. Let me go log mine again.

Mine are still in line with last time. Nothing more than 17 in the 8 range once warm.

 

I've spent the biggest part of the day reading HPTforums and haven't come up with a clue. I think it's time for a beer and a break.