RPM drop & recover after Warm engine start

[RFDRanger99]

I have a 99 ranger XLT 4x4, runs and idles great. Problem I'm having is after the engine is warmed up and i go to start it ie: run into the store and come back out, the engine will start and the rpms will tank to the point the engine almost dies, but then recovers, after that no problems, just starting it up after its already warm. I cleaned the MAF and no changes, I was thinking maybe the ECT for the computer, I have no idea what i can be because its not throwing a code

any help would be greatly appreciated

luke

 

[srteach]

Check the vacuum lines. Possible leak there.

 

[swtjames23]

replace your PCV valve, could be the culprit. It's dirt cheap and a 2 minute job