1992 5.0L mustang MS2 PnP, heads, cam, intake. Idle with AC on?

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AUBURN1111

Founding Member
Oct 17, 2000
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#23
No worries, Im in Greensboro for most of the day. I was looking at some notes I have on injector dead time and required fuel, what I have written down is way off what we have in the tune, but the car seems to run fine. I can't remember which were the numbers you gave me from your excel file for the SD 60 lb injectors. Im ready to see what this thing will do at full throttle.:cool:
 

a91what

SendMeUrDataLog
Mod Dude
Apr 6, 2011
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#24
I found a little time to take a look and adjust the fuel table for you. The crispy throttle will come once we have the fuel table closer. How is the idle doing?

go ahead and lean on it a little bit but watch the AFR gauge and be sure that it stays below 12.5ish
 

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AUBURN1111

Founding Member
Oct 17, 2000
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Mobile, AL
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#25
Ill try it out tonight, thanks! Idle seems ok, It seems to pause at 1500RPM then down to 900RPM, Ill try to make a log showing that, it doesn't drop to the point of cutting the engine off on deceleration with AC on or off.
 

5.0Thunder

Active Member
Jan 31, 2018
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#27
Looks like the fuel table just needs some cleaning, which is part of this process. A little lean in some places where it could use more fuel, quite a lot of cruise timing, though that might be perfectly fine.
 

AUBURN1111

Founding Member
Oct 17, 2000
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#28
Is VE Analysis good for some of this fine tuning? When I run it on one of the posted data logs with cell change to hard, it recommends very small changes to the VE table.
 

5.0Thunder

Active Member
Jan 31, 2018
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#29
VEAL is pretty good at getting your VE values accurate, though they typically need some manual smoothing after each session. Cell change should probably be Normal until it feels pretty good and the datalogs show the AFR's agreeing with the targets. At that point, you can set it to Hard for fine tuning. It's usually good to highlight your idle cells and lock them out of VEAL as well.
 

a91what

SendMeUrDataLog
Mod Dude
Apr 6, 2011
6,898
4,065
204
29
Hillsborough county
#30
If you are going to set the veal to normal it is best to use the longest datalog you can. What you can do is get multiple logs (one to the store, one back, one to work ect.) then when you go to open them in the MegalogViewer hold the Ctrl key and select the ones taken while driving on that tune. This will open them all in as one datalog and you will get overlapping data points, I have found this to be the most accurate method by far.
once that is done highlight the entire fuel map and hit the smooth function key.

You also need to remember that a 1 point change from a ve of 50 is a 2% fuel change.
 
Jul 7, 2005
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#31
If you are going to set the veal to normal it is best to use the longest datalog you can. What you can do is get multiple logs (one to the store, one back, one to work ect.) then when you go to open them in the MegalogViewer hold the Ctrl key and select the ones taken while driving on that tune. This will open them all in as one datalog and you will get overlapping data points, I have found this to be the most accurate method by far.
once that is done highlight the entire fuel map and hit the smooth function key.

You also need to remember that a 1 point change from a ve of 50 is a 2% fuel change.
Good tip as I didn't know you can open more than one datalog within Megalog Viewer at one time.
 

AUBURN1111

Founding Member
Oct 17, 2000
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Mobile, AL
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#34
Im about to go drive some today, before work sends me out of town for the rest of the week. I noticed hot start after sitting for a few minutes requires me to open the throttle just a bit to get it to start.
 

AUBURN1111

Founding Member
Oct 17, 2000
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Mobile, AL
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#35
Enjoy driving this thing! Still have some minor stuff to get figured out, hard to start after reaching operating temp and letting it sit a few minutes, any fast movement of the throttle seems to make it stumble and sometimes a slight back fire 2nd and 3rd gear.
 

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AUBURN1111

Founding Member
Oct 17, 2000
537
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Mobile, AL
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#39
Got a chance to data log tonight, I notice as I go into boost range of about 5-6lbs and about 3700-4000 RPM it feels as though the engine surges as though Im losing spark(did this before, decreased plug gap and it went away.) Im using all stock ignition, plugs gapped to .038 wondering if I need a stronger coil, re-gap plugs tighter, or if I'm way off in what I'm thinking is the issue. Attached current tune and data log.
 

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