rpms sticking?

[tweety2300]

Ok so if I'm cruising normaly and push in the clutch when I go to stop the rpms will come down to about 1500 rpms and stay there for a few seconds before coming down to the normal 700ish. It doesn't do this every time and idles normaly and no cel I'm not quite sure where to begin because it could be a lot of things. Any ideas its pretty annoying

 

[RABID_MP5]

hmm, when you come off the gas, the throttle body butterfly snaps all the way shut immediately - we don't have any dampers on that. So how else is the air getting there to do this? The EGR does supply air, albeit "dirty" and oxygen-deficient. But it's supposed to be closed at idle (which is the root of all our P5 EGR woes) I'm not sure how quickly the EGR solenoid is instructed to close and then actually close. An odd vacuum leak could also do it. But I'm gonna lean more toward the Idle Air control valve being sticky/dirty. It's the main thing that's supposed to be supplying and modulating the air other than the butterfly (Correct me if I'm wrong!). I've got a questionable one myself - just waiting on disassembly advice for cleaning it.

 

[tweety2300]

Well it hasn't done it since just the one day its kinda odd.my idle isn't bad moves around 50 rpms at most. Where is the idle air control valve? Itl be worth a shot cleaning its just confusing it did this one day and hasn't done it since although I havnt driven it much.

 

[chromal]

I could be crazy, but I think the ECU is helping you out with rev matching for downshifting. My 2010.5 MZ3 2.5l 6MT does the same thing.

 

[tweety2300]

Slowing down from 35 to come to a complete stop clutch pushed in the whole time?I could see it if it would have happened more than one day

 

[i12drivemyMP5]

I would make sure EGR & IAC are clean then check throttle cable and TB butterfly pivot too & maaaaybe the link to the cruise control unit to make sure it isn't catching somehow but that'd be long shot...after that, ????????????????

 

[chromal]

Yeah, no, it would have to happen every time you push the clutch after accelerating in gear, it would be consistent from the day you bought the car. I'm thinking upon re-reading this is something else entirely you're experiencing.

 

[tweety2300]

Well I have an mp3 so no vtcs or cruise. I've got a lot of runing around to do tomarow so ill see if it does it anymore. Its almost as if its on a cold start when it does it but its warm? Egr is pretty much ruled out because its idleing like its supposed to and its not an everytime thing. Not sure about iac and gas pedal has no no rough spots