Background: It has a tune, and I just bought the cable so I'll start poking around soon but I wanted some ideas first? Its a fairly stock evo8, 272s, stock injectors, exhaust, evo9 turbo, intak filter, Airflow based, not density, etc.

I get this weird decel issue right when I let off the throttle. It's like the ECU cuts injectors for half a sec, then adds injectors for the remaining second, and then finally cuts fuel all together. It is fairly annoying as this rocking is transmitted into the cabin. I've done searches but it seems like this issue is for the evo9...

I've also noticed that my low throttle is not very smooth, if that helps at all.

I've tuned standalones before, but this is style of tuning is completely new to me.

 

Closed or open loop?

Ecu kills injectors during decel motoring based on throttle position and Δ, and MAP. Usually takes 0.5 seconds or longer, but the key here - as it relates to the physical symptoms mentioned rests in the fact that if car is decelling with little or no throttle input, an AFR of lean or rich should not make a much difference.

There is probably an issue with pressure, like a BOV. A log of this happening would be like: a static TPS reading over rippling MAF, MAP, and RPM.

 

Ok, thanks. I will try and get that done. I'm used to AEM standalone so this is quite a bit different.

Sometimes it almost dies coming to idle when I haven't been decelerating first. It barely catches itself at about 400 RPM.

 

Dunno if you fixed your issue yet but that definitely sounds like a pressure issue like stated above. Check anything that would see positive pressure.

 

So boost leak check wouldn't be a bad idea?

 

As the engine now has cams you need to adjust the BISS screw on the throttle body so that with the AC off the steady idle steps is between 7 and 14. Preferably closer to 7 which is the stock setting.

This is not an instantaneous adjustment, as the ECU has to re-learn the idle settings.
Logging with Evoscan will allow you see what is going on.

That will get your idle and stopping issues under control and allow you to concentrate on the other point.

Do you have a Walbro fuel pump fitted?

 

Thanks for the info. I got the tactrix cable, just need to find some free time to start learning how to use it and I need to buy evoscan.

I do have a walbro.