I'll start this by saying I am relatively incompetent when it comes to doing my own maintenance.

When in drive at a stop my 2000 4runner rpm will drop from 600/650 to 500 and will shudder. The rpm will go back up to 600 and continue to fluctuate between 600 and 500 (shuddering at 500).

Recently changed out the battery and wasn't an issue before the battery was replaced.

Any ideas of what could cause this?

 

Vac. leak would be my first guess. Look for the small rubber hoses that have broken or come off the fitting.

 

Put some miles on it. When it gets a new battery, its new enough that the ecu needs to relearn.

 

Is this causing the MIL to trip at all??

Could just be a learning phase for the ECM.

Although I never seem to have had this happen then it might be a auto transmission thing also.

 

For whatever reason, I've slipped the tranny into N at stop lights - for the last 13 years of driving my 4Runner. Just seemed like the thing to do.

It sits and idles smoothly. If I leave it in D, the idle drops (engine is under load).



Andreas