RAF & Desired Idle Airflow-Finally Conquered!
Being a noob sure has it's challenges. I swapped cams recently and was able to just fudge my RAF #'s to get it started, idling, and driving. I knew though, that it was off because when I logged LTIT & STIT, the #'s were PN -.40lb/hr and IN gear -.25lb/hr.
I found the Russ K "idleconfig" files and got everything loaded up in my scanner, and tried the cold start idle test. The #'s it gave me when entered into my RAF tables would then NOT allow the engine to start, and then it would not idle. I was running 9's in the 198 column BEFORE (these were the #'s I fudged), and then putting the 7.3 into that same column that I came up with from doing the idle test resulted in a "no-start" "no idle" condition. I can only guess that the LTIT & STIT being active skewed the results in the DES. IDLE A/F log.
In all the posts all across the internet NONE of them discuss shutting off Adaptive Idle Airflow mAX/min in gear, and max/min in PN. Well, none of them except this one;
https://www.performancetrucks.net/fo...tricks-373848/
So, I fought with this for several days-each time going back to the artificially inflated #'s I chose the first time to keep it driveable after each new series of RAF #'s failed. Only after finding that link and seeing what he says about disabling LTIT and STIT in order to log desired airflow was I able to get it figured out. An AHA! moment for me for sure. This morning I did the desired a/f log again and came up with some decent #'s. Higher than the previous #'s (mid 8's), but lower than the 9's I fudged. I amended my RAF #'s, burned it, and the truck started right up and idled more cleanly that it had before. I knew though that driving it would be necessary to get it 100%. That is another thing that you hardly see people discussing on the net-after changes to the tune, you really MUST drive the vehicle for a short period of time at a minimum. I've found that driving it will bring the IAT's down, and also allow the trims to start polishing up any rough edges. When I first started tuning I would make changes and expect immediate results-like within seconds of starting the engine. I've now realized it takes driving the vehicle to allow the computer to polish up any rough spots you miss, or leave behind.
Tomorrow morning I will do the Desired Idle Air log again for PN, and update it again. Then when I finally get the PN rows done, I will then start on the IN GEAR rows. This is our winter here in the South. Today it was 71 degrees. Hard to get the lower cells when your winters are so mild. Anyway, I'm beginning to stray so I will end this.
Just posted so that hopefully anyone else struggling with this may find this post, and the link included, and FINALLY get their RAF in-line. Once you get those little tid bits of information to unlock the puzzle, it does get easier.
