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car stalls with a/c on

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Old Jul 14, 2009 | 06:45 PM
  #31  
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From: Northern KY near Cincy
The only draw back is that many of us on here who help others do it just to help our fellow man; while others do whatever they can to make a buck.
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Old Jul 14, 2009 | 10:03 PM
  #32  
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Originally Posted by Appauldd
I forgot all about this thread.

I have my AC issue completly resolved. Below is the things I did to cure it. Yes it is a lot.

Raised Idle zone timing (below 1250 rpm and below 50 laod) to 11
Opened up the BISS quite a bit (opened until I heard it hiss, then back in 1 full turn)
Raised the ISCV for AC on lower two block to 60 and 70
Increased other ISCV tables lower two blocks by about 10 each
Increased AFR in the 500 rpm and 80 load in below to 14.4
Raised the Idle RPM with AC on to 1234
Adjusted idle error tables to start with 0 and go up to 8
Raised idle stability timing control sensitivity to 150
thank you for this information.....this has been driving me crazy, will try it when i get home.

c
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Old Jul 15, 2009 | 04:31 AM
  #33  
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From: Northern KY near Cincy
Glad to see we are all getting the AC stall issues solved.

Who says we can't have big cams, ported heads, hard pipes, and, yup.....a MAF sensor? ? ?
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Old Jul 15, 2009 | 04:43 AM
  #34  
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Weird... I had no problem with my AC on driving the other day... guess I was lucky...
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Old Jul 15, 2009 | 04:51 AM
  #35  
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From: Northern KY near Cincy
Try the adjustments I posted. You should see good results.
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Old Jul 15, 2009 | 05:04 AM
  #36  
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My car has the same problem but I'm running an aem ems on a stock MAF big no no so I got the 5 bar map sensor coming in this week then retune
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Old Jul 15, 2009 | 05:05 AM
  #37  
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^ Uhhh... I had no problems
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Old Jul 15, 2009 | 05:08 AM
  #38  
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From: Northern KY near Cincy
Lucky....no....English Racing tuned...yes. I am sure they took care of the AC for you.
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Old Jul 15, 2009 | 05:08 AM
  #39  
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^ really?? My tuner told me to order the bar map sensor and a couple ppl on here told me the same asoon as I come to a stop it wants to stall on me sometimes it does and sometimes it doesn't LOL
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Old Jul 15, 2009 | 05:11 AM
  #40  
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From: Northern KY near Cincy
Originally Posted by EVOjuan623
^ really?? My tuner told me to order the bar map sensor and a couple ppl on here told me the same asoon as I come to a stop it wants to stall on me sometimes it does and sometimes it doesn't LOL
Getting the sensor will allow you to remove the MAF. Then you can re-tune to run in any conditions. Speed Density works ! ! Oh and you will need an Intake Air Temp sensor too (IAT sensor)
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Old Jul 15, 2009 | 08:17 AM
  #41  
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Originally Posted by Appauldd
Lucky....no....English Racing tuned...yes. I am sure they took care of the AC for you.
No what I am saying is I didn't have to change any of the other stuff you changed... just upped the AC on idle...
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Old Jul 18, 2009 | 09:57 AM
  #42  
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i have this issue as well. so i might try to play with those settings. i have a IX with stock cams and a aggressive Mivec map. i had to adjust my mivec map in the idle portion because it would hang the RPM's around 900-1200 when coming to a stop at times. but since now its hot as heck here i run the A/C now and i have noticed that it will want to cut off on me at times when coming to a stop and pushing the clutch. it actually only died on me 2 times thus far lol. it doesnt do it when i let the car come almost to a stop while in gear, same as OP. my car also has a lighter flywheel. i did some adjustments last night so i'll see where what it does next time out.

thanks for the info!
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Old Jul 18, 2009 | 08:27 PM
  #43  
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I think I got my a/c solved by adjusting the biss up and the changes you made appauld. Also P'm'd you appauld.
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Old Jul 19, 2009 | 03:48 AM
  #44  
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From: Northern KY near Cincy
Originally Posted by bambooi
I think I got my a/c solved by adjusting the biss up and the changes you made appauld. Also P'm'd you appauld.
PM'd you back.

For the masses......The A/C stall issue is mostly caused by the load increase that the car sees when the AC compressor kicks in. By logging the condition you can adjust your timing table to adjust for the increased load.

On a stock ROM timing table, you will see in the 60 load that the timing jumps a ton. I believe this area to be the stock load that engine sees with the AC on at idle. Thus, the higher timing.

But, several factors come in to play as well.
MAF Hz must be stable
AFR must be in check
RPM must be correct
ISCV steps must be correct
Timing needs to be spot on

Just take your time and make ONE CHANGE AT A TIME because every car is different. In my case it took a ton of adjustments because of the ton of mods I have.

Happy Tuning !

Paul
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Old Jul 20, 2009 | 02:01 PM
  #45  
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From: Kazakhstan.Astana
Originally Posted by lan_evo_mr9
I had the same problem... Here's my idle stepper values that rectified it...
190
150
125
125
100
65
15
10
The above is for AC off... Here is AC on
180
164
153
147
133
103
40
32
Those are the "desired ISCV initial step" maps. Target idle with AC on is 852 and 844. I have no issues with stalling with the AC on anymore.
Thanks, its worked for me ...
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