PDA

View Full Version : Idle tuning... more info on tutorial please!



vxleather
July 12th, 2008, 08:48 PM
Hi, have had a break from efilive and tuing for a while, basicaly fried my brain... needed a rest. Amounst other things. Anyway have gone back and revisited the Idle tut... something i could not get my head around prevoiusly.

I have a 232 /234 112lsa cam, 225 dart heads, extractors, standard TB, cold air intake, udp.... threw a built 4l65E with a 4200 stally into 3.9 diff gears..

I have issues when cold especially in the fact it will idle fine when in park... put it in gear it is fine till you start to roll / move then it starts to stall and carry on.

So I thought I would start here..I am trying to understand grams/per sec in these tables and there relationship... eg more grams per sec lifts the idle or drops it... etc etc...

Rafig makes sense sort of...

but the tables mentioned in the tut don't realy seem to understand what they actually do... i understand the txt in the tut when he say go up or down in htese squares but why??

http://i222.photobucket.com/albums/dd200/vxleather/EFI%20LIVE%20SCREEN%20SHOTS/DirectAirflowCorrection.jpg

http://i222.photobucket.com/albums/dd200/vxleather/EFI%20LIVE%20SCREEN%20SHOTS/LearnedAirflowCorrection.jpg

Eg by changing the figurs in these tables i am changing the amount of air in or not aloud in correct...?? these tables confuse me..

If this don't make sense well.... what can i say..

Anyhelp would be good..

Shane

5.7ute
July 15th, 2008, 04:40 PM
Shane,
The way I understand these tables is that they set how much airflow is added or removed from your short term & learned idle trims depending on the difference between your desired & actual idle speed. For instance if your desired idle speed in gear was 980 rpm & your actual was 900 rpm two things would happen. First is the 80rpm low drive table in B4515 would add 0.023438 g/sec as a direct correction. Also the low drive table in B4514 would add 0.019531 g/sec to your learned correction to try prevent a repeat of the problem.
There has been a few threads on this but none have come up with any solid answers.

vxleather
July 15th, 2008, 11:18 PM
thanks, that helps.... have re-set the tables back to factory... and work my way up...

SSpdDmon
July 16th, 2008, 03:44 AM
I forgot I moved the pictures. I'll have to get some new screen shots and re-post them. You say when you start moving. Once you're moving, the active idle controls are suspended. In other words, the screen shots you posted above - those tables aren't active. When you're moving, the spark is controled primarily by the high/low or base timing tables and the IAC is working off of the Desired Idle Airflow/Cracker/Follower tables. If they aren't playing nice with each other (and the fueling too), your idle at a slow roll will be irratic. :)

In the Idle>Parameters folder (IIRC), there should be two cells that define idle (where the active idle controls are active). One is based on throttle position and the other based on vehicle speed. ;)

vxleather
July 16th, 2008, 12:11 PM
thanks mate... did a log this morning as soon as it hits 3 kph it stalls out... after having a good read of the paremiters... the table B4311... throttle cracker avtivationis set to 3 kph...
http://i222.photobucket.com/albums/dd200/vxleather/EFI%20LIVE%20SCREEN%20SHOTS/throttlecrackerparemeters.jpg
so then looked at B4309 and let the log play as soon as it went from the 0 out cells to a cell that had a figure it stalled.. so i have reduced the figures in these to cells and will try it again tomorow.
http://i222.photobucket.com/albums/dd200/vxleather/EFI%20LIVE%20SCREEN%20SHOTS/B4309.jpg


As soon as it made it to 58deg ect it would not stall... lumpy but no stalling.

Shane