slight hesitation and high idle, going lean

[Rays_240]

Recently my sr has been acting a little odd. Ever since i installed the motor it has always idled high, around 900-1000 rpm steady. I have tried adjusting the idle air control valve without any luck. Maybe im doing it wrong but it never would change at all. Now my new problem witch Im not sure if its related or not is a low rmp hesitation. whenever I try to accelerate from under 3 grand my wideband goes lean off the gauge and it hesitates for a second and then goes rite back to normal. Im not sure if the lean condition is a cause or effect.

Now Ive only had my wideband for a few days i noted some odd stuff. While im just crusing with very light throtle it seems to stay very lean 16-17 or bounces back and forth between 14-16.5. When Im full throtle at full boost(14) it it goes down to 12.2-12.3 wich seems to be ok??

I just have a stock redtop with exhaust, front mount, intake, runing 14 pounds with a walbro 255. I have checked my plugs and tps sensor and both are fine. I dont think the fuel pressure is a problem because it seems fine under full throttle. I have been doing alot of research but nobodys problems ever seem to be the same as mine and they never seem to find a solution.

[Rays_240]

nobody has any sugestions? I keep getting this on and off and yesterday I started getting missfiring while it was bogging

[Rays_240]

I tryed unplugging my 02 sensor to see what it would do and it worked. No more hesistation and the car drives alot better. wideband doesnt jump around so much. It sucks though because this sensor is only a year old. So before I go and drop some money on a new one does anyone think it could be somthing else?

[Rays_240]

ok so even with the o2 sensor unpluged its still doing the same thing, just not as bad? I need some help guys, Im not sure where to go from here

[Morph]

With the RPM hesitation is it only when or worse when the engine is cold?

If so i would clean/change the IAVC, search about cleaning there are mutiple threads on how to do it.

BTW are you pushing 14lbs on a T25?

[Rays_240]

The hesitation does seem to be worse when its cold. but would the IAVC valve cause a problem even when I'm driving? Yea Ive been runing 14 pounds on the 25 for awile, no problems, doesnt run lean on boost or anything.

[Rays_240]

alright, I cleaned out my IACV with some carb cleaner. It seemed dirty but didnt help anything. I also have a new symptom. While sitting at idle my car will sometimes start to go lean off the wideband reading and stumble. I tried spraying around the intake manifold with carb cleaner to see if I could find a vacuum leak but I couldnt find anything.

Come on guys help me out here!!