[BORKAT]

My 2003 9-5 Aero has a rough idle. We hooked up a tech II to my car to change some things and look at the rough idle. It's missing in cylinders 2 and 3 when it's at idle but not if you give it gas. There is no check engine light or codes. Any ideas? This is what we tried so far.

1. Spare DI
2. Airflow meter
3. Looked for vacuum leaks
4. New plugs
5. Fuel pump

Has this happened to anyone else? Most people seem to be stumped by this issue.

 

[Kermit]

Crankshaft position sensor problem? What plugs did you use? Was the spare DI checked on another car for a misfire count?

 

[fordestroyer]

crank sensor?
throttle body?
fuel pump even?

 

[mt.aero]

Clean your injectors.

 

[mt.aero]

I didnt think of this before, but check the compression on those cyliders as well.

 

[gghh]

+1 check compression

 

[photousa]

Do some checking on this site regarding broken / cracked wires inside the throttle body. After everything you've already done, the throttle body issue would the next suspect. You'll probably end up needing your throttle body rebuilt by BBA Reman...

 

[mt.aero]

Do some checking on this site regarding broken / cracked wires inside the throttle body. After everything you've already done, the throttle body issue would the next suspect. You'll probably end up needing your throttle body rebuilt by BBA Reman...

Remember that this misfire is cylider specific. A bad throttle body would likely show up with random misfires accross all cylinders.

 

[photousa]

This is what I was referring to:

http://www.saabcentral.com/forums/showthread.php?t=156446&highlight=throttle+body

Agree with Kermit, is your Spare DI a used part? Possibly it's bad...
Plugs gapped properly?

Running a good quality fuel injector cleaner and a tank of premium 93 octane gas couldn't hurt..