986 S problem at idle, engine won't rev and shakes, battery disconnected

[Gorthaur]

Hey guys, sorry for posing this question in this topic but I think we should consider what I came through after disconnecting the battery (even though we actually don't know whether the problem was related to bad fuel or the cluster job).

I'm going to replace the window regulator in the next weeks. Am I supposed to disconnect the battery (since I'll have to disconnect the airbag as well)? Can I do the whole job without touching the battery?

As far as I know, I should not turn ignition on with the airbag disconnected in order to prevent the correspondent light to come on on the cluster, is this right?

Thanks for your help, cheers.

G.

[Meir]

Originally Posted by Gorthaur

Hey guys, sorry for posing this question in this topic but I think we should consider what I came through after disconnecting the battery (even though we actually don't know whether the problem was related to bad fuel or the cluster job).

I'm going to replace the window regulator in the next weeks. Am I supposed to disconnect the battery (since I'll have to disconnect the airbag as well)? Can I do the whole job without touching the battery?

As far as I know, I should not turn ignition on with the airbag disconnected in order to prevent the correspondent light to come on on the cluster, is this right?

Thanks for your help, cheers.

G.

i disconnect the battery almost every time i work on the car. never had issues.
if disconnecting the airbag (i.e. steering wheel, door panels, seats), wait at least 15 minutes between battery disconnect, to airbag disconnect.
the reason for that is, the airbag system includes capacitors that keep the system alive, even if the battery is damaged (like in an accident for example).
just make sure when you disconnect the battery, that the ignition is off. in fact, better if you keep the key in your pocket this time
in some cases, when the battery was disconnected for a long time, the RPM in idle are not stable at firs star up.
you need to drive the car for a wail, so the ECU and the MAF sensor can synchronize.

[Gorthaur]

Originally Posted by Meir

i disconnect the battery almost every time i work on the car. never had issues.
if disconnecting the airbag (i.e. steering wheel, door panels, seats), wait at least 15 minutes between battery disconnect, to airbag disconnect.
the reason for that is, the airbag system includes capacitors that keep the system alive, even if the battery is damaged (like in an accident for example).
just make sure when you disconnect the battery, that the ignition is off. in fact, better if you keep the key in your pocket this time
in some cases, when the battery was disconnected for a long time, the RPM in idle are not stable at firs star up.
you need to drive the car for a wail, so the ECU and the MAF sensor can synchronize.

Thanks Heiko. Good point.

Thanks Meir. The question is: my car features the optional alam. Will keeping the key in my pocket and disconnecting the battery activate the alarm?

[Meir]

Originally Posted by Gorthaur

Thanks Heiko. Good point.

Thanks Meir. The question is: my car features the optional alam. Will keeping the key in my pocket and disconnecting the battery activate the alarm?

i have the alarm as well. it doesn't' have a back up battery (at least in the US version), so no problem with that.

[Gorthaur]

Originally Posted by Meir

i have the alarm as well. it doesn't' have a back up battery (at least in the US version), so no problem with that.

I read somewhere the EU cars differ from the US cars right on that...

For "frank" do you mean the front trunk?

[Meir]

Originally Posted by Gorthaur

I read somewhere the EU cars differ from the US cars right on that...

For "frank" do you mean the front trunk?

front trunk = frank

as for the alarm.
disconnect the battery without the ignition key on. worst case the horn will go off. you can always reconnect the battery and disarm the alarm.
if that happens, you can do what you did last time.
please let us know how it worked for you, i worked on Porsche cars for 4 years, i don't recall any spacial behavior with the "European" style"alarm system.
if you got an aftermarket alarm system, that's a different story.

[Meir]

MOST IMPORTANT!!!
if you are disconnecting the battery, make sure to put something in the frank latch.
i used a rag, to prevent the frank from locking.
now i just moved the emergency cable to the right air vent so it is more accessible.