Weird hesitation at idle...

[S197steve]

Over the past week or so I seem to have developed a weird little hesitation or stumble when the car is idling. I noticed it Thursday while sitting at a red light. The car just sort of hesitates (not sure how else to describe it) and RPMs drop just a shade, maybe by 100 or so. I can actually hear it in the exhaust, sounds like the exhaust gets a tone deeper for that 1/2 second or so it stumbles. It almost feels as though there is a very mild cam with the way it almost stumbles when just sitting there. The car drives perfectly fine whether I'm WOT or just cruising along.

Any thoughts?

BTW, I've had the blower on for a little over 3 months with no issues otherwise. Changed the plugs and injectors at that time.

 

[Corpo]

bump, same problem?

 

[Corpo]

Because your vehicle’s engine is electronically controlled by a computer

some control conditions are maintained by power from the battery. When the battery is disconnected or a new battery is installed, the engine must relearn its idle and fuel trim strategy for optimum driveability and performance. To begin this process:

1. With the vehicle at a complete stop, set the parking brake.

2. Put the gearshift in P (Park) (automatic transmission) or the neutral
position (manual transmission), turn off all accessories and start the
engine.
3. Run the engine until it reaches normal operating temperature.
4. Allow the engine to idle for at least one minute.
5. Turn the A/C on and allow the engine to idle for at least one minute.
6. Drive the vehicle to complete the relearning process.​

The vehicle may need to be driven 10 miles (16 km) or more to relearn the idle and fuel trim strategy.

found this in a search

i'm gonna try this​

 

[Torch Red GT]

same problem here

 

[GrnBullitt08]

I had this same problem....are all of you running performance tunes? When I was running my stock tune I never had an issue, but once I loaded the performace tune it seems to do it occansionally at idle but goes away once you clear it out or you driving. Seems like the car gets a little overloaded with fuel...I would think its something in the tuning.

 

[Torch Red GT]

yeah im running a custom tune, i think that theory makes sense.

 

[Corpo]

I followed those instructions and it fixed it.