A9L idle issues

Decipha's custom GUFX strategy covers all 89-93 foxbody ecu's including the 88 mass-air california ecus.
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

A9L idle issues

Post by Badassbird »

I have an 86 Mustang that was A9L swapped. When I started to tune this it showed some weird idle instability. I went to work referencing Decipha's notes and was able to get the IAC at 33 to 38% and also checked the TPS voltage to be .94 to .95V. It seems that the car will never go into adaptive idle unless the clutch is depressed. The timing will stay static 20 deg. with no correction until the clutch is depressed and the idle speed control status flag reads -1 (dashpot control I believe) at all times. I believe this is my instability issue because it does idle much better with the clutch in. Any ideas on this issue?
decipha
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Location: Metairie, LA
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'25 F-150 5L

Re: A9L idle issues

Post by decipha »

is it setting closed throttle mode?

does tprel read 0 at closed throttle ?
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

Post by Badassbird »

A couple of weeks ago I was logging and tuning this 86 A9L swapped Fox just fine before having an idle issue. I took a break, did some research, updated software and hooked up the AEM WB to Pin 27/5V and Pin 46/Ground. The car is running well and takes changes but when I log I get a bunch of jibberish numbers in all PIDs and some wont log at all. Any ideas what I have done?
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

Post by Badassbird »

It seems that when I try to add anything to my datalog, for example RPM, then it will scramble other things.
decipha
Posts: 6384
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'25 F-150 5L

Re: A9L idle issues

Post by decipha »

Theres no such thing as adding anything to the datalog its a simple on and off button its either logging or it isnt.

What are you doing exactly?
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

Post by Badassbird »

In Binary Editor you have dash 3 which has the list of PIDs available to the strategy when not logging. Some are unchecked. There were some PIDS that were necessary that weren't logging. Come to find out I needed to check the ones I needed and save the payload as another name to get them to log. I am trying to get adaptive idle to work but it only works when the clutch is depressed. You asked me in another thread what TPREL is but I don't see the PID in the list and cant log it.
decipha
Posts: 6384
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'25 F-150 5L

Re: A9L idle issues

Post by decipha »

That explains it, no one here uses BE.

sounds like the datalogging patch in BE is corrupt

Tunerpro is far superior in logging. Simply click no setup required.

I just re read your OP and it sounds like TRLOAD isnt set to 0.
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

Post by Badassbird »

TP Rel is reading 0(sometimes 1) and the TP is 194 but still get no adaptive idle spark or ISC activity. ISC Flag is -1, spark source is 0 and Cl Throttle Flag reads nothing. Fuel error is 2-4% even with the idle unsteady. I am on Tunerpro and A9L2 now BTW.
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

Post by Badassbird »

You the man. I didn't even see the TRLOAD. It was on 3. Set to 0 and now adaptive idle works although I have never seen a stock motor idle this crazy unsteady. Idling above target at 38% dc with .1 or higher DESMAF PID N. Should be negative I would think.
decipha
Posts: 6384
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'25 F-150 5L

Re: A9L idle issues

Post by decipha »

.1 means its having to add air to reach idle

thats means your throttle stop needs to be opened a touch
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