Like title states, My evo stalls only when I depress the clutch on decel with ac on. The rpms drop to ~500rpm and sometimes stalls, and sometimes it catches. It only does it with the ac on and clutch in while decelling. I can sit at a stop with the clutch in or out and rev the engine and it will not drop the RPM's.
Car is mostly stock with the just a cone air filter and TBE, stock rom, stock flywheel. No boost leaks at all and the BISS is adjusted correctly with evoscan.
I believe it has to do with coasting fuel cut, is there anyway to adjust that with ecuflash. If I hold it in gear while decelling, I can feel the engine catch the idle in gear at about 1000-900 RPM and then I can push the clutch in and the idle wont drop.
I have also tried adjusting the ISCV tables AC ON and that does not seem to help the initial idle drop, only once the idle recovers(if it doesnt stall) it seems to raise the idle.
Also tried raising the AC on idle, but that does not effect the initial idle drop either.
Any other suggestions?

 

Idle air controller maybe? They're know to go bad, with similar symptoms. Also check that the MAF sensor is not gunked up from over oiling an aftermarket filter. Theres a write up on here somewhere that details checking the IAC for the correct voltage.

 

i had that happen to my 8 and it was the idle air controller

 

It idles fine with the ac on after the idle dips, and it seems as if the IAC is working because the idle raises when turning the wheel when stopped, and adjusting the idle RPMS with ecuflash. Maybe it isnt reacting fast enough though? The car only has 35k miles though...

 

Adjust here. It can take some time to dial in, but the car will idle fine and catch itself. Also, only adjust neutral, drive has no effect and appears to be a carry over from an automatic car.
Dan

 

Yeah, look into those idle tables.

But you could defy look into cleaning the MAF too. Although the can says no to Mitsubishi MAF, just spray further away with the straw.

 

I cleaned the maf. no improvement. I just ordered a brand new IAC see of that fixes it.

 

Brand new Iac, no improvement...

 

Have you done a boost leak test to see if you have a vacuum/boost leak anywhere??

It might be that there is a slight bit of air coming in after your MAF.

 

call a evo shop and ask.

 

No boost leaks at all, and the intake pipe is well sealed.
I did raise the AC idle a bit and the AC on ISCV steps we will see if that helps, if not I'll see is Tom from TScomptuning can fix it up.

 

Update, raising the AC on ISCV steps seems to make the problem worse. also raising the AC on rpm to 1000 still doesn't help the initial rpm drop. I am at a loss here. It seems that the IAC isnt catching fast enough and the idle dips and then it tries to recover, and raising the ISCV steps just seems to exaggerate the problem.

 

Have you set the BISS correctly using EvoScan?

 

Yes around 800 rpm with SAS activated, fully warmed up no accessories on.

 

What are you target idle RPM tables? 800?

It need to be set the same RPM as your idle target tables, if you have changed them.