E38 with 90mm TB and Crappy idle

[Naf]

Ok, i tried everything and i even got a pro tuner to fix my tune. Mid to up top the the engine runs fine. But when it is idling, and low RPM its not smooth at all. I tried increasing the MAF and timin, but my TB always remains at 18-20%

I recently increased the TB from stock to a 90mm and so far i havent had any code, but the occasional backfire and slow responce at low rpm...

If i max out the B2804 will my tb start to behave at low rpms and will the idle also clean up since the TB is more reactive? I have also increased C0806 & C0806 to be like the camaro. Which is the car i got the TB from. Will i brickify my ECM or will i be fine?

I have a 6.0Ltr with ported LS3 heads and a ported intake manifold. I also have a full escalade catback and 1 3/4 headers with HF cats. I will be installin a 100mm MAF with 102mm tubing once they get here...

[Naf]

drilled a 4mm hole in the plate and the idle smoothed out but when i come to a stop the idle drops way down then surges...I did everything i could...

Its just annoyin me

[swingtan]

Post the tune, some logs and a list of anything else done to the motor. If it's just a bolt on motor with no CAM, then no hole should be required.

Simon

[Naf]

i have a 216/228 500 lift cam now but am upgradin to a 224/236 with 550 lift...

My TP was always @ 24 deg but now after the hole its 15-20 dependin on ac.

I read through the sticky last night and will be attempin to calm the idle.

My caddy with a 102mm tb and a monster cam doesnt hunt or surge as bad as my truck. And it has the stock settings for the idle, it puts out 550rwhp and 505rwtq.

I really do not understand this whole issue, but this truck has always had issues with the new engine...

[Naf]

I followed the sticky instructions and found something very interesting...My max idles are opposite to the norm.

MAX 1 is 2.816773
MAX 2 is 1.759338

So far i only have a little bit of droppin while pressin the brakes, i need to work on the area a little more.

Timin is 18 degrees which is the stock settings.

When i install the new cam i will see what needs to be done to hold the idle and i will also have he new intake tube made so there is no restrictions at all

[Naf]

I have been tryin to follow the sticky after i changed the catch can and i am losin the battle here...

AC off everything is sort of fine, except MAX 1 just wont drop below 22 deg with no auto corrections
AC on everything is wrong LTFT goes to negatives

ARGH!!! what am i doin wrong???