IAC idle issues

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ajy113
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Joined: Mon Jan 09, 2012 6:06 pm

IAC idle issues

Post by ajy113 » Tue Jul 22, 2014 7:54 pm

I cant get my IAC to settle down around my idle speed, 848 rpm. It was fluctuating +/- 150 rpm or so....so I tried kicking up the idle as mentioned at the end of Idle air 101 and doing some quick math to get into the ball park. Now when I reloaded the new values and turned the throttle body stop screw back 3/4 turn the idle shoots up to 1600 rpm and then hangs I don't know where in the hell the 1600 rpm is coming from as I don't have any adders near that high? After a short period it drops but doesn't go lower then 1350 and just stays there with ISC flag at 2 for rpm lockout. All I did was update Neutral idle air and ITHBMA and this started....I attached the tune and my last quick data log ...any advice appreciated
Attachments
A9L 7-22-14 2014_Jul_22_20-28-36.zip
(21.5 KiB) Downloaded 113 times
A9L 7-22-14.BIN
(56 KiB) Downloaded 216 times
'90 foxbody, 351w 76mm turbo, f cam, tw170 heads, 80lb injectors, pmas MAF, Moates QH GUFB strat

ajy113
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Posts: 8
Joined: Mon Jan 09, 2012 6:06 pm

Re: IAC idle issues

Post by ajy113 » Wed Jul 23, 2014 6:33 pm

I found it, PSRIBN was out of tolerance....I somehow had a 1 in there when parameters are -1 to 0.

However I still have a surging idle that I cant seem to figure out. I'm using closed loop spark control and it helped, also dumbed down the KPSI scalars and ISC correction rate but I still get a hunt ....

Idle air seems close to dialed in, I've dumbed the ISC down ALOT, I also have a screen in front of the MAF meter. Any suggestions? Posting tune and quick data log from tonight
Attachments
A9L 7-23-14 fn860 change RPMDED increased.BIN
(56 KiB) Downloaded 180 times
A9L 7-23-14 fn860 change RPMDED increased 2014_Jul_23_19-00-23.zip
(148.01 KiB) Downloaded 102 times
'90 foxbody, 351w 76mm turbo, f cam, tw170 heads, 80lb injectors, pmas MAF, Moates QH GUFB strat

decipha

Re: IAC idle issues

Post by decipha » Thu Jul 24, 2014 9:35 am

just skim over the notes in the idle air write up and you'll be fine

remember

ithbma should be at the most .1 to .15 less than fn875n
iscdc should be below 35% at warm stable idle
ipsibr will be 0 or less than 0.05 when all is dialed in

if converting to the mechanical idle control be sure to clear the kams to clear the ISCKAM corrections, they will never be allowed

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my0wn3ds
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Re: IAC idle issues

Post by my0wn3ds » Wed Jul 30, 2014 5:43 am

How to convert to the mechanical idle control?
1994 Mustang 289EFI EECIV Moates Quarterhorse/C4
1987 Cougar XR-7 302EFI EECV turbo project/AOD
1993 Mustang 2.3L/T5
1997 Ka 1.3L/IB5
ex-1992 T'bird 3.8L
ex-1989'Probe GT 2.2t

XantheFIN
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Location: Finland

Re: IAC idle issues

Post by XantheFIN » Wed Jul 30, 2014 7:26 am

my0wn3ds wrote:How to convert to the mechanical idle control?
By decipha - Idle Air 101 # Mechanical

Helps? No?

P.S. don't think i can otherway help. I am not right person right now. :mrgreen:
European Zetec - GSAZ1 - ENVY

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my0wn3ds
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Re: IAC idle issues

Post by my0wn3ds » Wed Jul 30, 2014 7:36 am

XantheFIN wrote:
my0wn3ds wrote:How to convert to the mechanical idle control?
By decipha - Idle Air 101 # Mechanical

Helps? No?

P.S. don't think i can otherway help. I am not right person right now. :mrgreen:
Great link!
Need some time to understand))
1994 Mustang 289EFI EECIV Moates Quarterhorse/C4
1987 Cougar XR-7 302EFI EECV turbo project/AOD
1993 Mustang 2.3L/T5
1997 Ka 1.3L/IB5
ex-1992 T'bird 3.8L
ex-1989'Probe GT 2.2t

ajy113
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Posts: 8
Joined: Mon Jan 09, 2012 6:06 pm

Re: IAC idle issues

Post by ajy113 » Thu Aug 14, 2014 2:23 pm

Just an update on my post - I ended up having a corrupt tune that was making my ISCDC bounce around constantly amongst other things. Re-loaded onto a fresh A9L2 upload and everything working now.
'90 foxbody, 351w 76mm turbo, f cam, tw170 heads, 80lb injectors, pmas MAF, Moates QH GUFB strat

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