high mileage intermittent rpm drop @idle

[p93teal]

Cold or hot, after running and coming to a stop and waiting more than about 30 secs, the rpms drop and slowly recover. The 93 with turbo has 130k miles. Previously there was a throttle lift lash that seemed related to oil contamination in the maf. Cleaning the maf reduced the lash affect. I searched the Corral and found a possible electrical connections cleaning idea, and I plan to r&r the egr valve, and lastly the plugs are 3 yrs old and shall be replaced. The iac was cleaned already. Any ideas on the rpm drop, recommendations, or points to other references on the web or in books?
P 93 teal

[frdfandc]

Cleaning the IAC only goes so far. How much did it change when you cleaned the IAC?? If it didn't change much, itprobably needs replacing.

The EGR usually doesn't need replacing unless it is throwing codes. Check your KOEO & KOER and see if there are codes stored in the system.

[RdRunnr]

Check the battery cables and make sure they are still good and not all gunked up, especially the ground connection at the timing block.

[p93teal]

Thank you for the ideas. The grounds, and battery connects, and the ko off and running codes. Will do.

[p93teal]

got code 34 on koeo. vaccuum on egr and koeo still 34. I have a evp -(senor attached reading the egr valve) on order. PIck up tomorrow morn.

[2MUCHBOOST]

Sounds like to me the car needs a SLUDGE kit. It goes between the IAC and the TB.

[p93teal]

egr codes were cleared with new egr and evp (egr sensor). Idle problem continued until teflon safe throttle body cleaner was used on the tb and a junkyard IAC replacement went in. I used berryman chemdip (carb cleaner) on the carbon side of the iac and the teflon safe spray on the electrical side. Then the Motorsport idle reset procedure was applied. Gone is the idle drop to rough after 30 seconds, gone is the idle whiplash of rpms at throttle lift, gone is driveline lash at throttle lift.
p 93 teal Cobra, turbo, aod