Okay whenever I install a new PCM tune or the battery goes dead I get a rough idle for a short time that does eventually go away. The idle is set at 950 RPM but will drop to around 500 RPM or so then climb back up to normal.

After about the second or third short drive this issue is gone.Engine runs great with no other issues period.

IS this the PCM just learning and populating cells and blocks?
Is this normal?

 

Mine always did that after my longtube install. It would take a weeks worth of driving before it would clear up. I always dismissed it as the PCM relearning.

 

Normal, IMO.

 

Never happened to me. I started my car up with a new setup after it's been sitting for ~7 months and it found the idle right away.

 

The further off your BLMs are, the more of this effect you can have.

 

That makes since, my idle (cell 16 I think) BLM's are a bit screwy while the rest are just fine. Thanks guys.

 

yeah, it has to relearn. Mine does that too... its kind of annoying at stoplights, as mine seems to die, but after a couple times drinving and shutting it off and starting it, it eventually relearns the blms and stuff..

 

Just indicates that your tune is off. With a good tune it shouldn't have to learn much at all.

 

with the tune being off.

 

Excellent point, I am still on a mail order tune.
Now that the 9" rear is insatlled I am hoping to hit the dyno very soon for a good tune.