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1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
02-23-2007, 01:56 AM
Post: #1
1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
Hello I have a recently acquired 1996 SAAB 900S Convertible with 2.3 liter 4cylinder engine.  I love the car and have taken it to the Swedish Solutions (Saab/Volvo repair shop) and the check engine light is on.  They had me replace the Air Mass Meter (to the tune of $370) + another A.I.R. Pump.  However the car is still stalling out when at idle for a long time or when I am in congested slow moving traffic.  I love the car, but need to get to the bottom of this problem.  Any other theories or diagnosis would be appreciated.


I was reading about the stalling out problem.  Other owners/people said they replaced many parts and all they had to do was use higher octane fuel and since then it never stalls.

Someone also said = After much research and testing, I've narrowed down the main problem (stalling and poor idling) to the transmission. Apparently these automatics can develop problems with some governor seals and/or the torque converter lockup solenoid. In light of this, I'm going to have an experienced transmission specialist look at it sometime soon

Lastly someone said the Crank Shaft sensor is bad cost ($160 brand new).  They recommended that a  SAAB specialist cleaned the Crank Angle Sensor and that seemed to cure the problem and to be prepared to have this done at every service.

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02-23-2007, 04:58 PM (This post was last modified: 02-23-2007 04:58 PM by CaryJoeYork.)
Post: #2
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
I would like to do somemore research on this one. I do have two questions. Any recent repairs? What is the mileage?

Cary Joe York
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02-23-2007, 05:59 PM
Post: #3
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
I bought the car with 198,000 miles and it how has 199,800 something. The Repairs I have do are.
:rolleyes:Brand NEW Air Mass Meter
:rolleyes:Used AIR Pump from wrecked saab in junkyard (had 67,000 miles on it) and same part number.

Other than that I have no other repairs done. Thanks for taking time to look into this for me. I would really like to fix the vehicle. Summer will be here before you know it.
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02-23-2007, 06:43 PM
Post: #4
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
WinkI was doing some more research and came by this INFORMATION: What do you think about it?


The following is the adjustment procedure for basic idle on saab
900/9000's 16v with the gold colored aic valve that has three wires
connected to it.
Tools needed are:
1. A wire about 2 foot long with male connector on one end and a clip on
the other end. "The test wire"
2. A 1/4" drive driver handle or ratchet with 7mm socket and short
extension. "To loosen the throttle switch"
3. A 8mm 1/4" drive socket "To loosen the lock nut on the adjustment for
the throttle screw"
4. A small streight blade screwdriver "For turning the throttle screw"
5. A ohm meter "For checking the adjustment of the throttle switch"
6. A small jump wire "For bridging the throttle switch connector on the
wiring harness at the throttle switch"

1. Allow saab to reach operating temp. "fans cycling".
A. make sure a/c is turned OFF

2. Locate the test connector wire.
A. On 900's it is located behind the a/c evaporator box, near the gang
connectors and is green with a red stripe "single wire with plastic
connector on the end"
B. On 9000's its on the bulkhead on drivers side near the hood hinge
"rectangular dark colored connector usualy with cover on top" The proper
connection point is the pin that is closest to the driver and engine"
standing with your toes pointed at the center of the left tire side,
extend your right hand outward at 45 deg. and there it is. Its the
connector furthest to the right and closest to the center of the car.

3. Ground the test wire "with the saab idling"
IF- STALLS or idles very very slowly about to stall...
= "Basic idle needs to be adjusted"
IF- NO CHANGE "the system may have the basic idle speed set a little
high OR the throttle switch may be out of adjustment.

4. Remove connector at the throttle switch and bridge the center wire
and the wire closest to the driver "#1 & #2 the numbers are under the
boot on the connector its self." Use tool item #6.

5. Loosen the throttle switch " 7mm socket, tool item #2 " make sure it
will rotate.

6. SET BASIC IDLE: Loosen the throttle adjustment screw lock nut and
turn the screw clock wise to increase speed " use tool item #3 & #4 "
SET THE IDLE SPEED TO 750 - 800 RPM with the test wire grounded.
Disconnect test wire and the engine speed should rev up and settle
down to a good idle. repeate the connection and disconnection of the
test wire and observe the function as stated above.
IF disconnecting the test wire and there is no change = check and make
sure instruction #4 is in order. OR smack the AIC valve with a screw
driver handle and see if it tries to smarten up after repeating the
IF so = the AIC valve may be sticking.

people wait untill the AIC valve sticks in the high idle position,
before buying new valve.
IF you set the basic speed too high you will not notice any change in
rpm when you ground the test wire. Back off on the throttle adjustment
slightly untill you get a change. Lock the throttle screw down "8mm nut"

Take your multi meter, turn it on and set to ohms or cont. touch the
end of the test leeds together and observe the value "0" "this is a
Disconnect the leed ends and observe the value "OL" "this is no circut"
A. Connect the test leeds to pins #1 & #2 at the throttle switch.
Rotate the switch untill you get a circut "0", Tighten down the 7mm
hold down screws. Open and close the throttle and observe:
1. Circut at idle "0"
2. No circut at open throttle "OL"

Disconnect bridge wire and test wire and reconnect the throttle switch
wire harness connector to the switch. YOUR DONE

NOTES: The sympthons of basic idle speed out of adjustment are : stall
at start up, stalls or tries to stall on deceleration and the problem
becomes more pronounced with the a/c turned on. The concept is the basic
idle has to be adjusted to a certain point in order for the computer to
control the idle speed. As the aic valve opens it allows the engine
speed to increase as in the case of when you turn on your a/c, the load
of the compressor slows your idle down - the computer see's this and
opens up the aic valve to increase idle speed.
THE CAUSE: The throttle bore becomes coated with carbon sludge from the
pcv system, therefor restricting the clerance "opening" between the
throttle plate and bore. Less space = less air flow for idle= less idle
speed. In many cases all you need to do is spray carb cleaner into the
throat of the air horn on the intake manifold, brush with a tooth brush
and spray off again, reassemble and your idle should be up to par.

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02-23-2007, 06:47 PM
Post: #5
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
THE reason I posted that is because the symptoms I am experiencing are similar.

At Start up the car Stalls and tries to sall on deceleration (in traffic or coming to a stop). The Throttle bore must be coated with Carbon Sludge because the car has such High miles.....right? So it must be restricting the clearance "opening" between the
throttle plate and bore. Less space = less air flow for idle= less idle
speed. Rolleyes
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02-23-2007, 11:54 PM
Post: #6
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
I would try cleaning the T-Body first. Use an old toothbrush and some T-Body cleaner. Then use some Mopar Combustion Camber Cleaner. This is great stuff and the instructions are on the can. The part# is 04318001AB. You can get it at any Chrysler Dealer in the parts dept. Other than that I have some articles I will paste below. There are five of them. Each individual one starts at the the heading Original Message. Good luck and let us know how it goes.

_____________________ ORIGINAL MESSAGE _____________________

Hi all Saab techs out there. This problem is driving me crazy.
And it's not only this V6 but several others too. This one
starts up really rough once in awhile and sounds like it's
running on 3-4 cylinders. If I don't do anything,just let it
run it will clear up after about 1min and run perfect after

During this startup a lot of values is going haywire on the
Tech 2 screen, like Inj time,timing,AMM signal,calculated and
actual airmass idle control, Etc..

I do beleive that all this signals is in fact second degree
problem and happens because something else is wrong.

On top of this problem the engine stalls at idle once in
awhile, hot or cold without any warning signs. Have so far
checked ground signals at ign coil and ECU, plus powersignals
listed below.

Have replaced ign switch on several other V6,s with similar
problems but this one and two others got me stumped. Does
anyone now of a software update that maybe correct this
problem, or is it still a "gremlin" hidden in the ignition
power circuit.

Thanks beforehand

___________________ TEST AND REPAIR DATA ___________________

Checked for codes and none were found.


Fuelpressure - 40-50 Psi ECU Power + 30 - No drop
Antitheft/ECU power - No drop ECU power +15 - No drop


Replaced Ign switch, another shop replaced Ign coilpackage

________________ FIX ADDED ON May 6, 2002 _________________

Hello all Saab techs out there, this is a comment to my own
post from last year about sudden stalling and idle surge on
several 900 with the V6 engine. I finally got some info from a
friend that works at a Saab dealer. He faxed me info papers
that could be related to my problem.

It was the same info as I knew about already,and several of
you techs out there sent me last year, like ign
switch,redundant ground wire for AMM, plugwires and fuelpump.
BUT!!! One paper mentioned that the 94-95 V6 with Motronic
have problems with, listen to this. Idle flare up,hesitation
and sudden stalling if the TECH2 is hooked up to Motronic to a
length of time, like 20 min.

This is because of data overload in the memory, and after
awhile the ECU dumps the memory, causing one or more of the
symptoms described. This doesn't affect the adaptive memory or
trigger a fault code, and it have no harm for the engine.

So, with that info in hand I tested one the cars for the whole
day, and sure enough, every time the Tech2 was hooked up, I
had the problems. Every time I removed it, the symptoms went
away. And that explains the crazy signals that the Tech2
picked up in snapshot mode but I couldn't trace with my
labscope, since no sensors or switches was acting up. And it
explains why the car some days could be sitting in the shop
for hours running perfectly and some days it would stall every
other minute.

You see, after many of my test-drives, I came back to the
shop, disconnected the Tech2 to download info to TIS2000 and
was sitting there looking at the snapshot while the car was
running in the background WITHOUT THE SCANNER HOOKED UP. And
other test drives I didn't really have any good snapshots to
download and left the scanner hooked up to the car.GO FIGURE.

So with this answer in my hand, I must have fixed the real
problem long long time ago with the new plugwires or the extra
ground wire for AMM or the ignition switch. Because some
customers haven't come back to us and others haven't really
mentioned that the problem is still there.

So I feel pretty confident to close this problem as a fix.


Hi fellow techs, This Saab got me on my knees and the customer
couldn't leave it anylonger. Got some responses to check
batterycable conditions and to add a extra groundwire to
airmass meter but non of them helped the car. I was really
hoping to get a solid answer to the problem since we have
several other customers with similar problems, all of them
being NG900 with V6 engine, and replacing ign switch have
cured some but no all.

_____________________ ORIGINAL MESSAGE _____________________

please help This 900s stalls intermittently. When it does
stall the warning lights do not light up as they should they
are, just barly lit. After this car stalls it will imediatly
start up as if there was nothing wrong. I have no time to
check to se if it lost spark or if it lost fuel. There are no
codes present. I have checked for voltage drops and poor
grounds and I have come up empty.

___________________ TEST AND REPAIR DATA ___________________

Checked for codes and none were found.

____________________________ FIX ___________________________

Thanks to everyone who replied. 12 replies and all correct. We
replaced the ignition switch after monitoring voltages and
seing the +15 ckt loose voltage. The car is back in service
and eveyone is happy.I have seen a few of these switches fail
but normally I see a complaint of some accy not working or
intermittant no start and on this one it was just a stall.
also I saw nothing drastic in testing voltage drops until
driving down the road? Thanks again to all of you!

_____________________ ORIGINAL MESSAGE _____________________

Hello fellow technicians, This Saab was towed in to my shop
with a no start condition. Customer said that it overheated to
the point that it cut off. The car started for me, but was
missing badly and smoking even worse out the tailpipe. After
concluding that we obviously had a head/head gasket problem,
customer said to fix it. I pulled the head and the gasket was
blown between cyl. #2 and #3. Sent head to the machine shop,
machinist said that the head was severly warped, but he could
still do it. OK, after completing the job, it has a VERY rough
idle and sometimes stalls. The idle at times fluctuates up and
down like it is hunting for base. Other times the idle is
steady, but very rough. Driving the car down the road, It runs
great. Any ideas or suggestions would be greatly appreciated.
Thank you.


New head gasket, intake gasket, exhaust manifold gasket,
plugs, distributor cap, ign. rotor, fuel filter, thermostat,
coolant temp sensor, and tempature sending unit.

____________________________ FIX ___________________________

Thanks to the many that replied to my request for help, I
appreciate your time and knowledge! Many of you hit it right
on the money, Cam timing was off. I readjusted and it was alot
better, in conjunction with a collapsed front lower motor
mount, which I replaced also, it now has a nice smooth idle!
Thanks again for all your help!

_____________________ ORIGINAL MESSAGE _____________________

Hi gents, Thanks for opening this e mail, customer complaint
on this vehicle is that sometimes, only in hot weather when
cruising along, and all of sudden coming to complete stop,
with clutch depressed, car will idle rough and stall, does not
always happen, car will restart fine,this only happens in hot
weather. And twice now car will start first thing in the
morning, and sit and idle at 400- 500 rpm, and does not
respond to gas pedal, but clears up and idles fine , any
suggedstions, don't know if two problems are related or not,
has anybody seen this problem before. thanks, john.



____________________________ FIX ___________________________

to date this vehicle has not come back, so I don,t know if
this vehicle has been fixed, I did do some cleaning of ground
circuits, cleaned the mass air flow meter, and cleaned and
lubricated idle air motor, I,ll have to wait and see

_____________________ ORIGINAL MESSAGE _____________________

HELP! Any Ideas? This car will hunt for an idle when cold at
times. At Times it will stall. Then It Will Drive fine and
then at times will seem like it starves for fuel. It Acts like
a bad Air flow meter when that happens. Fuel pressure Good. No
Codes Stored.

___________________ TEST AND REPAIR DATA ___________________

Checked for codes and none were found.


No Codes, All Systems Functioning Normal Per Scan. Grounds AT
Intake Cleaned. Main Ground Stud Cleaned. Replaced IAC Valve
Reset Idle Learn. Cleaned Throttle Body.

____________________________ FIX ___________________________

Thanks to all, This one is fixed. Replacing the AMM cured this
ill car.

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Cary Joe York
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03-12-2007, 08:43 PM
Post: #7
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
My wife hit a piece of ice recently and cracked the aluminum/magnesium oil pan so that is a New $700 problem. The oil is leaking slowly, but surely. I made an appointment at the Swedish Solutions (Saab repair) center for March 15, 2007 to get the Throttle Body cleaned. It costs $91 so I will see if this fixes the problem.

I drove the car last week and it runs fine for about 15 minutes, but after that it stalls out especially since the weather is getting warmer. In Ohio it is in the 40's and 50's so the car is acting up Royally. I will let you know if cleaning the throttle body works.
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03-12-2007, 09:39 PM
Post: #8
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!

Cary Joe York
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03-27-2007, 11:11 PM
Post: #9
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
Hello Joe I sold the car. I never found out what happened and what the problem was.
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03-28-2007, 06:00 PM
Post: #10
RE: 1996 Saab 900S Stalling at idle or in slow traffic...HELP!!
Thanks for the update.

Cary Joe York
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