A9L idle issues

Decipha's custom GUFX strategy covers all 89-93 foxbody ecu's including the 88 mass-air california ecus.
Badassbird
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Joined: 2025 Mar 23, 13:37
Location: Franklin,OH
Vehicle Information: 2001 Ram Air TA-900 Wheel, F1A Procharger
1988 GTA Trans Am
2020 Explorer ST
1986 Fox Body-Converted to MAF with 93 X3Z computer and harness

Re: A9L idle issues

Unread post by Badassbird »

Even with it idling 50 to 60 rpm over target?
decipha
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Location: Metairie, LA
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'25 F-150 5L

Re: A9L idle issues

Unread post by decipha »

whys it idling over target ?
Badassbird
Posts: 12
Joined: 2025 Mar 23, 13:37
Location: Franklin,OH
Vehicle Information: 2001 Ram Air TA-900 Wheel, F1A Procharger
1988 GTA Trans Am
2020 Explorer ST
1986 Fox Body-Converted to MAF with 93 X3Z computer and harness

Re: A9L idle issues

Unread post by Badassbird »

That is what I am trying to figure out. I haven't been able to find a vacuum leak but the adaptive idle seems to be adding a little even while the idle is a little over target. I does idle better though.
decipha
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Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'25 F-150 5L

Re: A9L idle issues

Unread post by decipha »

post a log driving around w idle
Badassbird
Posts: 12
Joined: 2025 Mar 23, 13:37
Location: Franklin,OH
Vehicle Information: 2001 Ram Air TA-900 Wheel, F1A Procharger
1988 GTA Trans Am
2020 Explorer ST
1986 Fox Body-Converted to MAF with 93 X3Z computer and harness

Re: A9L idle issues

Unread post by Badassbird »

Here you go. This was the first run after getting adaptive idle to work. You can see the timing being pulled back at idle bust seems that idle airflow adapt is still positive up to .1 at times. WOT load is really odd too. Wasn't enough load to get into enrichment and the load falls drastically from 71% after 2700 rpm. I changed the target base fuel so it will be in enrichment while I mess with it. I don't have a log after that change but should be pretty close to .87 lambda when I log it. It was only a few % from commanded after I made a change for the first pull in the log. Now this guy does have a ProM 30 MAF on it with 30lb inj. I left the injectors alone. Should I update the tune for the FRPP 30s even with the ProM 30 MAF? Would probably change my falling load. WB is AEM X btw.
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052925step3.bin
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052925first run.xdl
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decipha
Posts: 6068
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'25 F-150 5L

Re: A9L idle issues

Unread post by decipha »

That's a perfect example of what not to do. Surprised it hasn't hurt the engine.

The first time you went wot between 650 and 670 imaf counts it was 17% lean according to your wideband, o2s confirmed it was lean.

second time you went wot through 650 ad counts the wideband and o2s both confirmed it was 5% rich. It showed your fuel error .95 at wot (high slope)

before you did the 3rd wot the wideband died and just stuck reporting 1.24

interesting enough you reduced the maf up top by that 5%. That means it was perfect before and you changed it?? why?

the first thing you have to do before you can do anything is input the correct injector data in first and foremost.

you changed the perload scaling function to command enrichment at a lower perload? the correct way to go about it would be to reduce the 0 vac/0 boost load threshold in FN035 to increase perload.

however without the accurate injector data in and without all the SP** values corrected for the new injectors all of your changes are going to get undone later on when you actually tune it.

I copied the maf transfer back over from stock to correct your 5% lean out at wot.

You didn't decrease the crank PW for the larger injectors.

This should make her safer for now til at least you can fix the fuel system problem. Should be pretty solid though as she looked great.
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Badassbird
Posts: 12
Joined: 2025 Mar 23, 13:37
Location: Franklin,OH
Vehicle Information: 2001 Ram Air TA-900 Wheel, F1A Procharger
1988 GTA Trans Am
2020 Explorer ST
1986 Fox Body-Converted to MAF with 93 X3Z computer and harness

Re: A9L idle issues

Unread post by Badassbird »

Great thanks. I had the injector data loaded in the first iteration but was having awful idle issues which we sorted. I was just guessing that this Pro M 30 may not want the injectors accounted for. I always used SCT MAFs back in the day and didn't use any calibrated units. Thanks for all the help.
decipha
Posts: 6068
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'25 F-150 5L

Re: A9L idle issues

Unread post by decipha »

no such thing as a maf not wanting injectors accounted for

sure you can go in and rape the maf but itll never be consistent

Theres only one correct way to dial it in properly. In any iteration the injector data has to always go in first. Its impossible to dial it in properly otherwise.
Badassbird
Posts: 12
Joined: 2025 Mar 23, 13:37
Location: Franklin,OH
Vehicle Information: 2001 Ram Air TA-900 Wheel, F1A Procharger
1988 GTA Trans Am
2020 Explorer ST
1986 Fox Body-Converted to MAF with 93 X3Z computer and harness

Re: A9L idle issues

Unread post by Badassbird »

I see what you did with the WOT fuel multiplier and is a great idea when N/A so your fueling comes in on TP. Good way of making sure you hit PE without finding load values yet. Runs much better now. Fuel is pretty tight and spark is a little on the low side but good. Again thanks for the wisdom.
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badassbird_250530a v3.xdl
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Chris White 5.0_ProM 30_FRPP 30s_No cats_053025.bin
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decipha
Posts: 6068
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'25 F-150 5L

Re: A9L idle issues

Unread post by decipha »

I have no idea how you got those peak load values for fn035 but it wasn't even anywhere remotely close. You severely over inflated those values. Its dialed in now so should be all good.

I dialed in failed load for you to.

enjoy
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