Engine speed drops SLOOOWWLY after disengaging clutch

[Ronin]

I first noticed it when I took it to the track the first time, don't believe it was happening before. I see it happen to lesser extents during normal driving, but the greatest example is when I did a quick burnout, engine got up to like 4500ish, put in the clutch, took it out of gear, engine speed drops like a feather...took forever to get back to idle speed. Of course, it jumps to the right speed as soon as I put it in the next gear, but this doesn't seem right. Dunno if it's clutch related, but I can hear my TOB going, and my clutch has been slipping bad lately (replacing it along with the FW).

I could be mistaken and it's been doing this for a while, but I sure don't remember it being like this.

 

[D3VST8R96GT]

happened to me too ...cleaned my air filter, and it helped alittle ....havent fixed the problem to date.

 

[mike97gt]

theres something on here to "fix a hanging idle. putting a copper plug so to speak, drilling a hole in it and putting it in the IAC. i'm not sure where the procedure is tho.
my car used to do that until i bumped the fuel up abit on my sct. runs a little rich on top end but works alot better for me.

 

[2002BLGT]

MAF backwashing most likely , might need to relocate bypass valve or put a bigger one on the car

 

[Ronin]

MAF backwashing most likely , might need to relocate bypass valve or put a bigger one on the car

You know, I think there's something wrong with my bypass valve...I haven't been making the boost I should. Thanks for the suggestion, think I'll take the recommendation I got here earlier and get a Bosch (at least I think it was Bosch) unit.

 

[Willis_98GT]

you can modify the iac, google the iac mod, basically what it does is you space the iac and the plenum with a wider gasket and it tricks the iac into dropping idle faster, pretty neat and a must for all 5speed cars on the planet.

already did it to my mach and ive had it for less then two days!