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can someone take a quick look at this

  • Thread starter Thread starter cbarr300
  • Start date Start date Oct 3, 2006
C

cbarr300

Member
Jun 6, 2006
746
0
17
goose creek, SC
Oct 3, 2006
#1
  • Oct 3, 2006
  • #1
EDIT: Welp, i'm having some technical difficulties posting a datalog up soooo


I've been having some low load bucking, usually when i'm in first or second gear and I'm off the throttle is when it happens, though sometimes it happens when I'm slightly on the throttle. If I slightly accelerate it'll go away. I'm usually around 1500 rpms when it does this.

I took out some spark downlow (tweecer) and it seemed to somewhat help but its still pretty bad. My lambse's are around 17 or so which shows that I'm running rich (as does my wideband) so could it be that I'm running too rich? I've been messing around with the maf curve for the lower points and haven't made much progress with it (still learning)....so I'll post up after I lean it out a bit.

btw, it has a hardly noticeable buck in the lower rpms/load of 3rd gear and there's no buck in 4th or 5th

Anyone have any suggestions as to what could cause this low load buck?
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Oct 3, 2006
#2
  • Oct 3, 2006
  • #2
I'm not sure what I was seeing when I tried to use the link but

pulling back a little spark in the load rows is usually a good place to start with that kind of issue.

How about just a bit more info to explain what you did
and
Why you did what you did

Grady
 
C

cbarr300

Member
Jun 6, 2006
746
0
17
goose creek, SC
Oct 3, 2006
#3
  • Oct 3, 2006
  • #3
Well, I pulled back the spark in the lower rows because, using the search button , that's what I've seen cause the bucking. now it is at around 27 adv. when this happens instead of 45 or so...and like I said above, its better but not too much.

Is it possible the MAF curve could be the cause of this?

The fuel ratio is around 13.2 when this happens so I don't think that is tooo rich.

The only thing I could think of is that my maf is sending my computer some screwy signals and its reading from the wrong load rows


OOOHHHH, and when I'm looking at load in eec analyzer, do I look at loadx or load
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Oct 3, 2006
#4
  • Oct 3, 2006
  • #4
cbarr300 said:
Well, I pulled back the spark in the lower rows because, using the search button , that's what I've seen cause the bucking. now it is at around 27 adv. when this happens instead of 45 or so...and like I said above, its better but not too much.
Click to expand...

I understand and agree ... you'll just have to play with the values for the best results.

I use an older version of software and don't know if you can do this
but
if you can do it ... here is a tip for you

I can hit the space bar and kill the dlog when I am capturing data to hard drive.

When I wanna find an intermittent or random event such as you have described ... I just tap the bar when the event occurs and look at the data that precedes the end of the file.

Is it possible the MAF curve could be the cause of this?[
Click to expand...

Sure ... the curve is gotta be close in CL for optimum drivability.

The fuel ratio is around 13.2 when this happens so I don't think that is tooo rich.
Click to expand...

I would be more interested in what the K's have to say when the event happens.

At curise you are gonna be at very light load and the throttle is gonna be just barely cracked open AND at times not opened AT ALL.

I'd bet you see something in a range like .9 to 1.3 maf volts when the bucking at cruise thing occurs.

Not saying that is too fat
but
too fat will cause bucking and an unstable idle ... which is kinda sorta along the same lines you describe.

With a condition such as that ... It would not be all that uncommon to see ratios above 14.7 to 1.0

The only thing I could think of is that my maf is sending my computer some screwy signals and its reading from the wrong load rows
Click to expand...

It is possible ..........
Again ... Look at what lambse & K's are doing at that moment

OOOHHHH, and when I'm looking at load in eec analyzer, do I look at loadx or load
Click to expand...

Don't remember the exact answer
but
I can narrow down your search to find the info

Its all about how you got your load scaling switch setup

Thats about all I can think of for now

I bet Adam, Greg or some of the other tweek geeks will chime in

Grady
 
C

cbarr300

Member
Jun 6, 2006
746
0
17
goose creek, SC
Oct 4, 2006
#5
  • Oct 4, 2006
  • #5
well my Ks are at a constant .992-.996 when the bucking is happening. lambse's reading ~16 to ~18 : 1
I'm gonna lean off the bottom portion of the maf and see what that does. Thanx for the pointers Grady. I'll repost later on tonight...or rather today I suppose. I tell you, this self tuning thing most definately has a steep learning curve...like all things, just takes time I suppose....that and the search button and questions

oh yeah, I just click a button on my laptop which is similar to you just clicking the space bar
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Oct 4, 2006
#6
  • Oct 4, 2006
  • #6
cbarr300 said:
well my Ks are at a constant .992-.996 when the bucking is happening. lambse's reading ~16 to ~18 : 1
I'm gonna lean off the bottom portion of the maf and see what that does. Thanx for the pointers Grady. I'll repost later on tonight...or rather today I suppose. I tell you, this self tuning thing most definately has a steep learning curve...like all things, just takes time I suppose....that and the search button and questions

oh yeah, I just click a button on my laptop which is similar to you just clicking the space bar
Click to expand...

Just as you would expect ......

WB shows fat
K's pulling fuel
Lambse commanding leaner ratio

I understand about the thoughts of ....

"Will I Ever Be Able To Learn All This Stuff"

I felt that way for sure once upon a time

If you wanna go beyond simple mechanical adjustments .........

You gotta build a new knowledge database

NEVER FORGET THIS ...............

Each day you have more and more control over how your Stang behaves

AND

Its for both ... Cruise Mode ... as well as ... Max Go Fast Mode

Stay after it ... the results are MOST DEFINITELY worth your effort!

Grady
 
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