So i have owned my lovely 2000 S2K from 9K miles and we are just now about to top 215K all highway miles (140 mile round trips to work)

I have an odd and very unpredictable idle problem...

Scenario #1 (only happens very seldom ) Car is warm and running fine down the road, and i stop and the idle drops to 1 bar and back up to 1000RPM a few times a stays at 900 where it should be.
Scenario #2 Driving fine down the road, stop at a store, the car is idling fine for a few minutes, THEN IT WILL drop to 1-2 Bars and stay there barely fluctuating until it slowly works it way back up to regular 900. I mean it takes 4 times as long to get to normal that Scenario #1

NEED TO KNOW: THAT NONE OF THIS IS CONSTANT.

Scenario #1 9/10 times the drop in idle wont happen when coming to stop or pushing in clutch going into neutral
Scenario #2 sometimes it doesn't happen at all, and its not specific to the cars temperature (cold engine VS fully warm)

Things i have done to try and remedy this:
New Improved MAP sensor with zip tie holder from HardtopGuy
New IACV (cleaned the ports also)
New Up and Down stream O2 Sensors
New Berks Hi Flo CAT 60mm it think
Valve Adjustment (valve wasnt off much at all)
New Omni TPS Sensor adjust correctly
New PCV Valve
New Coils (all 4)
EUC Reset Procedure

From having a driving this car so much it feel like the ECU is never fully learning its A/F Ratios ETC, its like it forgets sometime then has to relearn and then is fine.

But its so random, it just completely throws me off, There is no CEL and it never dies completely unless i catch the idle drop perfectly with the gas pedal and thats like 1-2 times over 5 months.

Help!!!!!!!

 

Did you disconnect the battery to reset the ECU? On my car the idle never seemed to stabilize after I worked on the IACV but some time later I had to remove and reinstall the ECU and the idle was correct from them on. Don't know why but happy to have it cleared up.

 

my new hypothesis on the quirky behavior of the ap1 idle issues are going to be pointed squarely at the injectors

my theory is that they are probably leaky due to a weak spring over time and mileage inside the injector, but I haven't gotten a chance to swap in new injectors

 

Yes, i have done the ECU relearn 6+ times trying every situation i could think of IE car warm/cold/raining outside AND keeping revs at 3k 2k and just letting it relearn by driving it.... so yes ive tried it.

 

This is kinda where im at... thinking maybe a seal is going bad and this causes the randomness maybe????

I read on another thread where an injector seal was causing similar issues but there wasnt really enough info on there to help my situation.

 

Have you checked your TPS voltage ? may just be a simple TPS tweak do a search for how to do it.

 

let us know if you find the culprit please.

 

Yes i have replaced the TPS with the Omni TPS and adjusted it correctly (.49 volts closed 4.56 volts wide open )

After doing ( 4 months ago) this it seemed help with the smoothness of the car but didnt fix the idling problem :/

 

Still no verdict.... The problem seems to be getting worse these passed few days... maybe because it has been rainy and super humid down here in Alabama ??

Anybody know what is would point towards more if it seems to get worse on rainy /humid days when the air is super thick?

 

seems to point towards ecu if temperature is affecting it, map sensor maybe.