Revs acting funny..

[DaveFR]

Been having this issue for a while. Car is a evo 8 running mafless with apexi d jet. While engine is not fully warmed up, while driving and clutch in to change gear or neutral, the revs drop to a point when it seems like it is going to cut out and recovers itself by self reving twice and after that comes back to normal idle. Once car is properly warmed up revs are normal and steady.*
I have tried cleaning throttle body and adjusting bov. Also did idle reset by disconnecting battery. Problem still persists. Does it sound like idle control valve? Any links to a how to to clean or adjust icv? Thanks for all the help guys..*

 

[Evomad4]

did u do the idle reset, disconnect battery for few mins reconnect, let the car idle for 10mins with no electrics on then turn all electrics on let idle for further 10mins then go for a drive?

if so maybe check for small air leaks from the pipes ect if all checks out maybe try a base idle reset via ecvoscan

 

[DaveFR]

I did the full idle reset mate. No small air leaks found either. Don't know if i can use evoscan as am running a apexi d jet ecu? What controls the idle during cold start and stops after engine warms up? Problem is only during engine cold operation. Once its warmed up everything is ok.

 

[Evomad4]

ahhh right well there goes that idea...

what does the car idle @ when fully warm? could try turning the idle screw to up the revs a little i now a few people that have had the problem were the screw as moved and they have had to readjust it

 

[DaveFR]

Car idles about 800-900 rpm when fully warm. How do i adjust the screw? Was thinking removing the icv and cleaning it. Think it will help?

 

[B6lee]

Has to be a fueling issue. Best to get it looked at by Evo specialist

 

[DaveFR]

No evo specialist near where i live mate. In france.
If its a fuelling issue shouldn't it be all the time and not just when its cold?

 

[Evomad4]

other options are either icv or did u say u r running a bov "dump valve"? im running a hks ssq bov on mine and when coming to a stop the revs do drop low some times maybe try taking you bov off blocking the holes up and seeing if that sorts it

 

[DaveFR]

I am running a r-spec dual port dump valve. I understand it could be that but why does it only do it when cold. If the dump valve is suspect it should do it regardless of temp of engine i think? Prior to fitting that dump valve i had a turbosmart dual port as well but that was siezed closed effectively acting as a bung imo and the engine did the funny revs thing all the time and not just when it was cold. That led me the change the dump valve and everything was ok until recently when it started doing it when cold only. I have removed the dump valve and dismantled and cleaned and lubricated it and refitted. Still does it only when cold. Doing my head in this!!

 

[RsvRob]

Mapping issue on idle....

 

[DaveFR]

Map was not disturbed in any way mate. Only started recently therefore can rule that out i think...