bad idle after battery disconnect

[madeleine90]

Hello everyone i got some problems with my 95 MY00 B205E engine manual transmission after replacing the battery the rpm's in my car are dropping very low when it comes to stop (sometimes below 500 and theres a risk of shutting down the engine, so i need to keep my foot on the accelerator). When driving everything everything is okay, the car also starts well, only those RPM's drop when idle is the issue. When the car completely stops the rpm's are going back to normal. Before replacing the battery everything was fine. The battery is a dedicated one for saab's, a friend of mine checked also the voltage and its ok. There is no difference if i use the brake pedal to stop or not. Please give me some advice on this guys

[DanielZ]

With the limited knowledge I have I'd say it seems it may have almost gone into "limp home" mode. My wagon did this a few weeks ago after wife stalled it pretty violently.

It's at least easy to check and fix.
Others might have better ideas but it's at least a start. Sorry I can't be more help.

[madeleine90]

hey, thanks for your reply if you mean the thingy on the throttle body i had checked it and its not in limp home any more ideas? i mean, what could happen after disconnecting the battery? during research on the internet i saw that in many cars after replacing or when the battery got discharged the ECU could get resetted and the car needs to "learn" idle and that after some kilometers the issue should go away. Is this possible in saab's?

[nordwulf]

The low idle problem may not be related to the battery change.

Look for any vacuum hoses that may have come undone from the engine. Is the engine light on? Even if it is not on, it's always a good idea to scan for any OBD2 error codes.

There was a thread with a similar issue: http://saabworld.net/showthread.php?t=32086

Not sure if any suggestions offered in that thread are related to your problem.

[madeleine90]

Hello everyone, i have new problem...

So my issue with dropping rpm's on idle has gone away itself... After driving about 60 km's. Everything was perfect for 2 days, but yesterday at the morning when i wanted to go somewhere the car started for a second and then it turned off. Now its not starting at all Its cranking but not starting. Fuel pump is ok (i can hear it starting when turning the key for ignition), CPS was replaced 400km's ago (new one Bosch), today i got a second hand DI cassette for try, the car also started for a second and it turned off immediately. When it started even holding the acceleration pedal didnt keep it alive. What can be the issue now? tomorrow i try to check it with Tech2 for some error codes. I know i had from some time on my SID an info about key battery replacement, can it be an problem with the immobiliser? or any sensor witch can prevent the car from starting? (