Going rich then lean when shifting

Covers all sn94/95 mustang v8 ecu's.
decipha
Posts: 4899
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Going rich then lean when shifting

Unread post by decipha »

nope never had this problem that wasnt a simple fix
dleach1407
Posts: 468
Joined: 2021 Mar 21, 15:17
Location: Colorado Springs, CO
Vehicle Information: 95 Mustang GT, CBAZA Quarterhorse
331, 190 11R heads, Edelbrock Victor 50 manifold, F303, T5, 76mm Turbo, 91 octane, Returnless dual pump 03 cobra tank, Behind bars rails, 80# siemens injectors
wbo2_030MtxL

57 F100, RZASA, 04 Crown Vic ecu and harness, 302, GT40 heads, 4r70w, 80# deka5 shorties, Holley carb style throttle body, Speedmaster high rise intake manifold

Re: Going rich then lean when shifting

Unread post by dleach1407 »

I can only divide the existing value 2 more times. I can either use .13 or .25. Anything .07 or less goes to 0. I tried this last year and dividing it from 4 to 2, to 1, then to .50 and there has been 0 improvement.
dleach1407
Posts: 468
Joined: 2021 Mar 21, 15:17
Location: Colorado Springs, CO
Vehicle Information: 95 Mustang GT, CBAZA Quarterhorse
331, 190 11R heads, Edelbrock Victor 50 manifold, F303, T5, 76mm Turbo, 91 octane, Returnless dual pump 03 cobra tank, Behind bars rails, 80# siemens injectors
wbo2_030MtxL

57 F100, RZASA, 04 Crown Vic ecu and harness, 302, GT40 heads, 4r70w, 80# deka5 shorties, Holley carb style throttle body, Speedmaster high rise intake manifold

Re: Going rich then lean when shifting

Unread post by dleach1407 »

As I expected, Setting it to .13 or .25 made no improvement. In fact, the issue seems worse at .13 than it does at .25.
dleach1407
Posts: 468
Joined: 2021 Mar 21, 15:17
Location: Colorado Springs, CO
Vehicle Information: 95 Mustang GT, CBAZA Quarterhorse
331, 190 11R heads, Edelbrock Victor 50 manifold, F303, T5, 76mm Turbo, 91 octane, Returnless dual pump 03 cobra tank, Behind bars rails, 80# siemens injectors
wbo2_030MtxL

57 F100, RZASA, 04 Crown Vic ecu and harness, 302, GT40 heads, 4r70w, 80# deka5 shorties, Holley carb style throttle body, Speedmaster high rise intake manifold

Re: Going rich then lean when shifting

Unread post by dleach1407 »

Should I maybe look at transfering all of my data to a fresh t4m2 tune? This has been going on for 3 years with 0 progress made.
decipha
Posts: 4899
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Going rich then lean when shifting

Unread post by decipha »

Go the other direction with it. Increase manifold volume and dial in the bottom of the maf til you get it ironed out.
dleach1407
Posts: 468
Joined: 2021 Mar 21, 15:17
Location: Colorado Springs, CO
Vehicle Information: 95 Mustang GT, CBAZA Quarterhorse
331, 190 11R heads, Edelbrock Victor 50 manifold, F303, T5, 76mm Turbo, 91 octane, Returnless dual pump 03 cobra tank, Behind bars rails, 80# siemens injectors
wbo2_030MtxL

57 F100, RZASA, 04 Crown Vic ecu and harness, 302, GT40 heads, 4r70w, 80# deka5 shorties, Holley carb style throttle body, Speedmaster high rise intake manifold

Re: Going rich then lean when shifting

Unread post by dleach1407 »

Is there a way to view the log as a linear graph like BE instead of watching it play back? Is the MAF history running average an accurate way to look at the LTFT? mine seems to vary from what the LTST displays in the gauge view during playback. As an example, my idle LTFT is between 1 and 1.02 while watching it play back but the running average shows .97. Im thinking I dont know how to use the histograms correctly
decipha
Posts: 4899
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Going rich then lean when shifting

Unread post by decipha »

it also factors in the short term fuel trim as it shows the fuel error
PaulC-turbo5.0
Posts: 104
Joined: 2021 Feb 15, 21:56
Location: Lancaster New York
Vehicle Information: 1989 fox GT convertible
5.0 stock block, E7 heads, stock cam
Explorer GT40 intake flipped to driver side inlet
Single 67mm On3 BB turbo
Flipped JBA headers, custom SS 2.5" hotside built by me
custom 3" coldside thru On3 intercooler
tuning with Moates QH + TPRT
Dechipa's GUFX and supporting files, couldnt have tuned it myself without him!

Re: Going rich then lean when shifting

Unread post by PaulC-turbo5.0 »

I notice differences like that as well. Are we maybe paying too close attention to the fuel error at all times instead of the LTFT?

Here is a short log of what my car is doing. I pulled out of the driveway shifted up to 3rd to my corner, made the turn and then went up to 4th and stopped the log. There was only a very short hardly noticeable stumble shifting into the 3rd after the turn. I could live with this but would love to get it dialed in better.
shifting issue - 5-6-21.xdl
(53.16 KiB) Downloaded 178 times
When I got to work I held the throttle sitting in neutral at 200 and 225 IMAF counts to double check as I've always had trouble trying to dial these points in and it looks like it was off by 10% and 7% KAMs and FE were 1.10 and 1.07. I made those adjustments to the MAF transfer.
decipha
Posts: 4899
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Going rich then lean when shifting

Unread post by decipha »

perfect example why you should never have negative fuel trims

You need to go to fn1303 the accel enrichment table and kick up accel enrichment at that 100 ect
PaulC-turbo5.0
Posts: 104
Joined: 2021 Feb 15, 21:56
Location: Lancaster New York
Vehicle Information: 1989 fox GT convertible
5.0 stock block, E7 heads, stock cam
Explorer GT40 intake flipped to driver side inlet
Single 67mm On3 BB turbo
Flipped JBA headers, custom SS 2.5" hotside built by me
custom 3" coldside thru On3 intercooler
tuning with Moates QH + TPRT
Dechipa's GUFX and supporting files, couldnt have tuned it myself without him!

Re: Going rich then lean when shifting

Unread post by PaulC-turbo5.0 »

the car is cold though, once it warms up the trims are really close to 1, I actually brought them down some recently due to the recent conversations we've been having here on that subject. Are you saying this issue has something to due with negative trims? I have dialed and re-dialed the MAF again and again trying to fix this issue and it doesnt really seem to effect it.

Ok will do, should I multiply that entire row? and by how much double? I've never really understood the x axis of that table.
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