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View Full Version : Defueling?????



noff
April 5th, 2012, 11:40 AM
just wondering if anyone can help me out on this, ive went through every table and tried everything i can think of, for some reason right when i start to hit 2800 rpms i start loosing command mm3 and duration starts to drop, it always has on every tune i try . i got the tune of tune depot since i could not read my stock one any help would be much appreciated. i can even see it in the boost gauge too dont know whats going on with it, if anyone one has stock tune maybe send to me i would like to try that and hopefully fix my speedo problem too thanks alot

2007 5.9
April 5th, 2012, 11:43 AM
You the one who emailed me about this issue??

If so I'll be looking at it later tonight, and get back to you tomorrow or late this evening.

noff
April 5th, 2012, 11:56 AM
ya wasnt sure if it sent out right, thanks appreciate it

noff
April 9th, 2012, 01:08 PM
just posting this in case someone else is thinking there having a command drop problem

this makes sense to me now y i see command droped, but soon as converter was locked i would not drop any command

As the ECM senses load decrease..mm3 begins to fall. ECM doesn't see the need to keep the mm3 up if there isint sufficient load.
The level of de-fueling you are seeing is consistent with common nature of these...some OS don’t drop mm3 and some do. No real rhyme or reason. The level of drop isint hurting your power at all...remember mm3 is just a referenced value...not actual amount. As long as you are hitting your target, pulse, rail and timing given your mm3 values for those, then you are in effect NOT de-fueling.

Les Szmidt
Silver Bullet Tuning
silverbullettuning@gmail.com

FUBAR
April 9th, 2012, 01:39 PM
Also as Dan has previously stated, when actual fuel pressure falls below command, mm3 will raise to compensate for loss till pressure comes back up. Which is also parallel to engine load.

2007 5.9
April 9th, 2012, 01:46 PM
As was posted...the level of mm3 drop isint significant enough to cause duration loss.

IIRC, it was 145@2500 and by 3000 it was 133mm3...which was still high enough to achieve commanded duration.

As load decreased mm3 dropped off..as soon as load went back up, mm3 increased to 145.


I informed him that as long as his pressure/pulse were still being achieved, then it was ok.