car almost dies ONLY after boosting

[alIan]

I just replaced my IAC, which fixed my idle issues except for one:

when i give my car any boost above 0 PSI and then push in the clutch (allowing the rpms to drop), the idle doesnt catch. RPM's go all the way to zero, and sometimes idle recovers and sometimes it doesnt and the car just dies.

it's as if the car doesnt recognize that it needs to catch idle after the airflow changes dramatically (after a small boost).

Any suggestions?

oh i forgot to mention: the problem also occured before i upgraded my injectors and tuned my idle on the SAFC, so it shouldn't be anything to do with that... ALSO i am NOT VENTING... my greddy type S is recirced.

 

[majik2k5]

Check your BISS screw. For some reason, when I changed my IAC, I had to reset my BISS screw at a different location. Until I did, it just constantly stalled anytime you weren't giving it gas.

 

[alIan]

i did check and adjust my BISS, and got the idle right. This problem occured before AND after i changed my IAC.

 

[oldman]

1. What's the logger telling you at those dying moments?

2. At what rpm are you idling?

3. How much vacuum are you pulling at idle?

4. Have you pressure tested the intake tract?

 

[spoold]

mine did the same thing, if you boosted then let off completely it would almost die. i had a mild-bad boost leak going on, id recommend checking for boost leaks

 

[alIan]

idle is at 750 RPM +- 15, logger shows no CEL's (havent run a full log when i boost a tiny bit... but the car is getting full power under boost), pulling ~26 mmHg (cold, i think) vacuum at idle,

i have done a leak test, but i need to do another, as i dissassembled and reassembled since then a bit. i still do not forsee this being a problem, though, but checking is essential, i realize.