In reading the various posts on the throttle hanging issues,I have not noticed if there seems to be any correlation between hang on Recirc type BOV vs. VTA setups ? Or even if this is an issue on these cars as everyone seems very focused on the ISCV? setup,or idle control hanging or delaying the return to idle. Being a newb to the EVO world,I just thought I would ask,are these issues prevalent regardless of BOV style,and or if the car is SD(No MAF) or still running a MAF ? Or am I completely barking up the wrong tree here ? I guess I just dont buy that the IAC can bypass enough air to allow the engine to "hang"at 4K plus RPMs,and I wonder if reversion flowing into the air intake is "fooling" the MAF ? Input,and or criticism welcome,I am going to experiment myself just for personal satisfaction.

 

Most throttle hang has been with issues not related to the BOV.

I've seen it happen just by flashing the car.

 

But this doesnt seem to be happening in other Turbo cars,there must be some issue either in the tuning/code or how the throttle control/ISCV system is setup. It is NOT normal,even a little bit and honestly makes me nervous when pushing the car hard ! Perhaps Decel fuel cut tables(dont know if we have any) As compared to my Turbo LS2 vette,I have NONE of these types of issues. Do these still hang with,say and AEM,BS3 or other standalone setups ?

 

Throttle hang in an Evo is due to the ISCV and the Decel fuel cut tables. Different setups require different settings.

The condition first reared it's head when we were searching for a "universal" rom. We discovered that we had to use stock rom settings in some tables for the universal rom to work on all applications. EDM, USDM, and JDM all have different variables.

Early on we solved throttle hang by adjusting the idle stepper lookup table. It was later discovered that the decel tables are the better/accurate cure.

I am with Project Skyline.....throttle hang does not have anything to do with BOVs.

Hope this makes sense.

Paul

 

Thank you for the response. I will look into the Decel tables and see how the car behaves after some adj there. Like I said,being unfamiliar with EVO tuning,I had no firm idea of where to go and was grasping at straws.

 

Feel free to shoot me some emails if you need more assistance.

Same screen name at g mail dot com

 

+1

But the condition was not first discover when 9653 was release, but years before, when the IX were released.

It affects all 05+ cars/ROMs.

Like Appauldd said, at first we fixed it by modifying the Stepper table, but it was a crude fix and messed with cold start.

Then when the "universal" ROM came, the problem got attention again and we found the true fix, which is mainly the "Decel fuel cut delay" tables.


As a shameless plug, I offer services to eliminate the throttle hang. PM me if needed

 

As I recall, you and I solved this riddle.

 

Yep, we sure did And I helped find the first crude fix of editing the stepper table back in '06 (before we found the decel delay tables)

I was just mentioning that this problem first came up years ago, in '06, when the IX were released, not when the "universal" ROM was released, which is IIRC was in '08.

 

So do I need to switch ROMS, or just rewrite the decel tables ? I will PM one of you,since you obviously know what to do. Thanks again for the help,I REALLY appreciate it !

 

You just gotta read..... https://www.evolutionm.net/forums/ec...=throttle+hang

 

Thanks Jay....you beat me to it.

 

I had rev hang when I had boost leaks. I fixed the boost leaks, the rev hang disappeared.


Do a boost leak test just to cross that off the possibility list so you dont drive yourself nuts.

 

Since this car was freshly reassembled as a theft recovery,missing parts,before I mess with the tune anymore I think I will do exactly this.Thank you !

 

when you're talking about throttle hang is it in between shifts? i know with mine if im above 5k rpm and shift the rpms will step up about 1k from where it was.... i haven't had any issues with it per say, but it did strike me as odd. reminded of how the 370z's will match rpm to road speed while shifting but it only does it on the evo above 5k.