Car Stalls Like Crazy When A/c Is On - WTF?!
Car Stalls Like Crazy When A/c Is On - WTF?! Just got HP Tuners and fixed most of my problems with my idle, but when I turn on my a/c - ESPECIALLY when it's below 210* (still warming up), it stalls everytime.
Any idea what tables or numbers I can edit to help this problem?
Thanks!
Any idea what tables or numbers I can edit to help this problem?
Thanks!
Teching In
Joined: Oct 2003
Posts: 45
Likes: 0
From: Columbia,SC
In the idle section there is 4 rows. the top row should be idle in park without the a/c the secound row should be idle in park with a/c on. that is the section you need to change. your third row is the idle in drive without a/c. and your fourth row is in drive with a/c on, you need to change that also (unless you have a 6speed)
There is an A/C load torque field that might want bumped
up, but I think maybe the real problem is that the PCM
has a pretty poor idea about what torque you are making
from airflow at the low end after mods (cam), so the load
based adder maybe isn't being that effective. If you get
the VE more accurate this should improve some, but may
want to prop up the airflow first and then shave back on
it from a more stable point.
up, but I think maybe the real problem is that the PCM
has a pretty poor idea about what torque you are making
from airflow at the low end after mods (cam), so the load
based adder maybe isn't being that effective. If you get
the VE more accurate this should improve some, but may
want to prop up the airflow first and then shave back on
it from a more stable point.
Ok, tried all of that and it didn't amount to anything. Once the car warms up, everything, but still below normal operating temp, it stalls when the ac is on.
I know the shop I went to initially totally f$#ked up my tune, so now I have to try and undo what they did. Does anyone have a similar cam/mods to mine with a solid tune so I can see wtf it's supposed to look like?
I know the shop I went to initially totally f$#ked up my tune, so now I have to try and undo what they did. Does anyone have a similar cam/mods to mine with a solid tune so I can see wtf it's supposed to look like?
TECH Fanatic
Joined: Aug 2005
Posts: 1,691
Likes: 1
From: Sunny London, UK
Go back to basics and work forward.
Tune your VE, Idle using RAF, spark, afr etc.
Sounds like a basic issue but until your basics are done properly you will be wasting your time.
Tune your VE, Idle using RAF, spark, afr etc.
Sounds like a basic issue but until your basics are done properly you will be wasting your time.
Last edited by ringram; Aug 2, 2006 at 04:42 PM.
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Originally Posted by ringram
Go back to basics and work forward.
Tune your VE, Idle using RAF, spark, afr etc.
Sounds like a basic issue but until your basics are done properly you will be wasting your time.
Tune your VE, Idle using RAF, spark, afr etc.
Sounds like a basic issue but until your basics are done properly you will be wasting your time.
Just set it back to a stock tune. That's what I'm gonna do is start all over. The only thing that sucks is that I lose the WOT tune b/c I don't have a wide band.
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On The Tree
Joined: Feb 2004
Posts: 156
Likes: 0
From: Fayetteville, NC
I was having a similar problem with mine. A/C on the car would stall if I even thought about hitting the gas. Changed my A/C Offset Max/InGear to 3.40. Worked like a charm. No more stalling!
Originally Posted by TSDuke
I was having a similar problem with mine. A/C on the car would stall if I even thought about hitting the gas. Changed my A/C Offset Max/InGear to 3.40. Worked like a charm. No more stalling!
Changed my A/C Offset Max/InGear to 3.40.
Could you ellaborate a little on this? My Z-28 is doing the same thing and it's driving me nuts, thanks
On The Tree
Joined: Feb 2004
Posts: 156
Likes: 0
From: Fayetteville, NC
Originally Posted by 98-LS1
Changed my A/C Offset Max/InGear to 3.40.
Could you ellaborate a little on this? My Z-28 is doing the same thing and it's driving me nuts, thanks
Could you ellaborate a little on this? My Z-28 is doing the same thing and it's driving me nuts, thanks
I have a 224/230 .582/.570 112 in my TA, It does the same thing you speak of. Probably 80% of the time I use the AC. I have HP Tuners but havnt had a chance to mess w/ that problem yet. I'll keep an eye on this post, and also if I get a chance to figure it out I'll repost.
Originally Posted by TSDuke
I was having a similar problem with mine. A/C on the car would stall if I even thought about hitting the gas. Changed my A/C Offset Max/InGear to 3.40. Worked like a charm. No more stalling!
Make sure your fueling is correct and spark is relatively steady at the kPa and g/cyl that turning on the AC puts you at first.
On my 2001 ZO6 cam/header car, the timing would retard when the AC was turned on. Thanks to EC Tune, I went to Engine Torque > AC Torque > Max Retard, and set that table to 0. Now the timing doesn't retard when the AC is turned on. Don't know why GM did this.
Russ Kemp
Russ Kemp
hey, this is xtreme's friend - we are doing some ve tuning right now and will try the aforementioned change (thanks TS Duke).
The previous tuners of the car did a **** poor job, and we had to revert back to a stock tune. The old "tune" was mostly stock tables with the injector flow rate table changed.
Well both keep you all updated
The previous tuners of the car did a **** poor job, and we had to revert back to a stock tune. The old "tune" was mostly stock tables with the injector flow rate table changed.
Well both keep you all updated
The A/C offset is the key. Its too low for a cammed car.
The A/C offset lets the computer know how much air it needs to add to compensate for the a/c compressor's drag. With a cammed car, you may need 1.5 g/s extra air to idle with the a/c on, but if the offset max limit is 0.5, when you turn the a/c on youre going to be 1 g/s too short. Bumping up the max offset will let the computer learn how much extra air the car needs to overcome the drag from the compressor.
The A/C offset lets the computer know how much air it needs to add to compensate for the a/c compressor's drag. With a cammed car, you may need 1.5 g/s extra air to idle with the a/c on, but if the offset max limit is 0.5, when you turn the a/c on youre going to be 1 g/s too short. Bumping up the max offset will let the computer learn how much extra air the car needs to overcome the drag from the compressor.
hey guys, thanks for the help - changing the ac offset really did help out the idle. we then had problems with the car stalling (ac on) when disengaging the clutch under load. we ended up multiplying the idle->idle rpm->proportional -> "Airflow High/InGear/AC On" table by 2x across the board. It helped a lot, but may need more....RPM still kicks down low out of 1st gear. hope this helps others out as well
Originally Posted by Grimes
hey, this is xtreme's friend - we are doing some ve tuning right now and will try the aforementioned change (thanks TS Duke).
The previous tuners of the car did a **** poor job, and we had to revert back to a stock tune. The old "tune" was mostly stock tables with the injector flow rate table changed.
Well both keep you all updated
The previous tuners of the car did a **** poor job, and we had to revert back to a stock tune. The old "tune" was mostly stock tables with the injector flow rate table changed.
Well both keep you all updated
Truth. What I find most comical is the fact that the STOCK tuned computer LEARNED the mods better than what those morons tried to do.
well, the car seems to stall after the initial startup, but now it catches an idle ALOT quicker than before and keeps it .... this is with the AC off though. Havn't dared the ac on yet haha.
However, with the car in gear, it has been stalling randomly in 2nd gear mostly after i put the clutch in and try to coast. It's like it tries to catch itself at 900rpm, but then just plummets and stalls....
However, with the car in gear, it has been stalling randomly in 2nd gear mostly after i put the clutch in and try to coast. It's like it tries to catch itself at 900rpm, but then just plummets and stalls....
I have a similar size camshaft ie 224/228 0.581/0.588 112+1. Also, ported stock TB, air lid, and Pacesetter LT headers. Do you want me to email you my tune? Sounds like your base RAF, VE, and timing are not right and a slew of other little things mentioned above. Have you changed the Startup Frictional Airflow Initial?