Idles, drives fine, and strong but when coming to a stop it drops quite low in rpms

[kaganader]

Car idles perfect at 950rpm (where I have it set in link) But when moving and coming to a stop, when I shift into neutral it will drop down to 400-500rpms for a few seconds then bounce back up to 950-1000 and idle perfect again. This started after I blew off a vacuum port plug on the intake after a few pulls at E-town. I have replaced every Vacuum plug since I saw one cracking. Car is still doing it but it has not stalled on me yet.


IDC is 1.5% when idling normally but when it drops in rpms in the log when coming to a stop the IDC drops to 1% then goes back up to 1.5%. My idle Hg is 23Hg and when it drops in idle it goes to 20Hg. Could a vacuum line be cracked and expanding when I go into neutral or do I have a fuel problem?

 

[92AWDHX40]

Do a boost leak test to rule that out, then you can eliminate that.

 

[herms99gst]

Have you checked your iac to see if its functioning properly?

 

[kaganader]

ISC, Biss screw is all new. ISC is at 30-29 in logs on idle (replaced everything in the TB when I took it apart to clean it and freshen it up, only about 2 month old everything)

I will Do a BLT tomorrow since the sun is going down right now. Just weird how it pulls fuel when the rpm drops then adds fuel as it goes back to normal idle when almost the same amount of air is being metered.