Why are my fuel trims so damn inconsistent?
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- 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
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- 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: Why are my fuel trims so dang inconsistent?
So I was wrong on the A9L2 base fuel table my bad, it is .8. Thinking I should copy that table over and see how it does leaning it out a tad. Do I just have to change the base fuel table or do I need to multiply the MAF transfer as well?
Dleach keep us posted on the pressure change I am for sure interested in the results.
Dleach keep us posted on the pressure change I am for sure interested in the results.
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- 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: Why are my fuel trims so damn inconsistent?
When youre WOT, it uses the base table with no HEGO feedback. Assuming your maf is dialed in, simply changing the commanded fuel in the base table is all you should need. I would do a WOT pull logging wideband,Lambse and LTFT to see if its running where it is commanded. Assuming that is good, all you need to do is change the base table in those load/rpm values.
Ill let you know how the fuel changes go. I already modified the tune, just need to climb under the car and set base pressure to 60. I cant get my car out of my driveway for the next day or 2.. they just poured a new sidewalk that crosses through my driveway. Didnt want to leave my car outside until it dries so it will be a day or 3.
Ill let you know how the fuel changes go. I already modified the tune, just need to climb under the car and set base pressure to 60. I cant get my car out of my driveway for the next day or 2.. they just poured a new sidewalk that crosses through my driveway. Didnt want to leave my car outside until it dries so it will be a day or 3.
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- 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: Why are my fuel trims so damn inconsistent?
Ended up pulling my transmission to fix a hard shifting issue and to install a McLeod RST twin disk. While I had it up in the air, I changed the fuel pressure and loaded the new tune. I assumed I would have some MAF table inconsistencies which turned out to be true. At idle, it was off a lot more than in cells a few above it. Im assuming that is because the fuel was boiling in my rails while idling causing the inconsistent trims. I havent driven it yet since the initial changes. Ill know more in a few days.
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- Vehicle Information: 95 Cobra
Re: Why are my fuel trims so damn inconsistent?
dleach1407 wrote: ↑2021 Jul 07, 13:58Is this accurate?dleach1407 wrote: ↑2021 Jul 07, 12:20 I feel like instead I would do the changes to the high slope first, save it, then go in and change the remaining injector settings to the new settings for 60psi and return the maf and tps failure and cid back to the previous setting.
To be clear, is the following correct?
"return the maf" = re - enter the MAF transfer?
"return CID" = SARCHG?
Could you explain "return TPS failure?" I've not seen any info on this.
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'19 F-150 3.3L
Re: Why are my fuel trims so damn inconsistent?
search SP** and everything that needa to be updated when the high slope is changed
Injector high slope is the entire foundation of any tune
Injector high slope is the entire foundation of any tune