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  #1  
Old 28th March 2011
dwoolley dwoolley is offline
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Default Hesitation on Acceleration

I'm having some trouble with acceleration 1900 saab non Turbo, the saab will try to accelerate but at the low rev range it struggles and really hesitates. High revs are fine!

I swapped the AMM/MAF but I get the same issue, I unplugged the AMM to get limp home mode and get the same issue but worse. I tested the o2 sensors and it seems OK, getting .1V when lean and .9V when rich.

12223 is the error code.

Any suggestions?
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  #2  
Old 28th March 2011
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Raub Raub is offline
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Maybe a weak fuel pump? Clogged fuel filter?
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  #3  
Old 28th March 2011
Vollblut Vollblut is offline
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Fouled spark plugs? Bad petrol in the tank?
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  #4  
Old 28th March 2011
d_ames117 d_ames117 is offline
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I had a similar issue that was fixed by replacing the timing chain which had stretched to its limits throwing off the timing ever so slightly (or so it appeared, but it was the only thing I changed at the time and I haven't had the problem since). The symptoms were when trying to accelerate quickly from a stop the car would bog down and refuse to accelerate. However, letting off the gas slightly would allow the car to accelerating at a lower rate. Not a good thing when pulling out into traffic.

You may try checking the timing chain tensioner extension - 11mm is the limit for an old chain according to the greater minds on this forum.

Dustin

p.s. I assume you mean 1990
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  #5  
Old 29th March 2011
B202NUT B202NUT is offline
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Quote:
Originally Posted by d_ames117 View Post
I had a similar issue that was fixed by replacing the timing chain which had stretched to its limits throwing off the timing ever so slightly (or so it appeared, but it was the only thing I changed at the time and I haven't had the problem since). The symptoms were when trying to accelerate quickly from a stop the car would bog down and refuse to accelerate. However, letting off the gas slightly would allow the car to accelerating at a lower rate. Not a good thing when pulling out into traffic.

You may try checking the timing chain tensioner extension - 11mm is the limit for an old chain according to the greater minds on this forum.

Dustin

p.s. I assume you mean 1990
Slow the Rodeo Cowboy! Chain is a bit far fetched this early.

I had the same code last week. you checked the 02 sensor; BUT, did you check up in the preheater connector for corrosion? I am willing to bet my cash the 02 sensor is just a bit dirty; PB blast it and reconnect the preheater connection,

Remember the 02 sensor sends signal to the ECU to tell it how much fuel to deliver. Hence more than likely your lean codes.Disonnect the battery when you clean the sensor,,
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Old 29th March 2011
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Lambda probe (O2 sensor) is there to assist in the fine tune feedback loop.

99.9% of fuel ratio calculations are derived from the AMM, NTC, engine rpms and software fuel maps. The probe sniffs the output to confirm oxygen content in exhaust to qualify the calculations.

O2 sensor does not regulate the fuel delivery amount.
O2 sensor will not stop the engine running if disconnected.

It is a feedback source.
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Old 29th March 2011
B202NUT B202NUT is offline
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Quote:
Originally Posted by Rodentmaster View Post
Lambda probe (O2 sensor) is there to assist in the fine tune feedback loop.

99.9% of fuel ratio calculations are derived from the AMM, NTC, engine rpms and software fuel maps. The probe sniffs the output to confirm oxygen content in exhaust to qualify the calculations.

O2 sensor does not regulate the fuel delivery amount.
O2 sensor will not stop the engine running if disconnected.

It is a feedback source.

it will give the ECU a faulty reading if its corroded, which can cause lean mixture codes, that I know for sure!

I dont think he said anything about the engine not starting he said hesitation which can directly be related to the 02 sensor,.

my point was I would be looking there before pulling the timing tensioner. I am not guess working here. I had the EXACT same exact codes less than a week ago and cleaning and reconecting the 02 sensor solved the lean mixture codes: http://www.saabcentral.com/forums/sh...d.php?t=206839

Read your Bentley, when you pull code 12223; it send you to code 12225

12225 - incorrect 02 sensor output. Sensor preheat circuit may be open..

Checking the 02 sensor properly is the correct process of elimination in the fault tracing process; per the code. 12223 does not IMMEDIATELY suggest AMM or NTC.

I am just reading the book my friend and following the process suggested. Worked for me, but for all intensive purposes test everything..

Last edited by B202NUT; 29th March 2011 at 02:23 AM.
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Old 29th March 2011
dwoolley dwoolley is offline
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Well the hesitation is not there today, but not much driving. But I did notice the Check Engine light come on under heavy throttle, when I back off the light also goes off.

Code :12223

Im 99% the O2 sensor is fine. So i'll be checking for leaks, esp around the FI. change the plugs, maybe change the fuel filter. fingers crossed.

and yes its a 1990
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Old 29th March 2011
dwoolley dwoolley is offline
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Quote:
Originally Posted by B202NUT View Post
PB blast it and reconnect the preheater connection
what is PB blast?
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  #10  
Old 29th March 2011
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PB Blaster. Like WD-40 on steroids.
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  #11  
Old 29th March 2011
B202NUT B202NUT is offline
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Quote:
Originally Posted by dwoolley View Post
Im 99% the O2 sensor is fine.
I said dirty and corroded not faulty. but its your cup of tea your allowed to have it your way...
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  #12  
Old 29th March 2011
d_ames117 d_ames117 is offline
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Quote:
Originally Posted by B202NUT View Post
Slow the Rodeo Cowboy! Chain is a bit far fetched this early.
True enough, I wasn't getting a CEL with my issue. Although if there's no AC it's a fairly quick job.

Dustin
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  #13  
Old 30th March 2011
Rob22315 Rob22315 is offline
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I'm going through this on my 93 900S. My closest suspect is the AIC. I was getting periodic bogging down at low throttle openings and low RPM. High RPM and/or high throttle opening seem to be OK. I cleaned the connectors at the TPS and AIC (signs of obvious corrosion on both) and the behavior of the problem changed significantly. I now only get the hesitation for a brief period during warmup. The car runs fine otherwise. Before the cleaning, I would get bogging-down symptoms unpredictably at any time.

I believe the AIC connector or motor is faulty so the it's getting less air than normal as the AIC flutters aimlessly against a showering electrical input. I don't have 100% proof that this is the problem but I think I'm close because of the above behavior change after I cleaned the connectors. I've noticed the engine continues to produce power during the bogging-down episodes so it doesn't feel like a spark or fuel problem.

Also, at high throttle opening, I don't have the problem either since any air coming from the AIC would be inconsequential.
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