UPDATED - PROBLEM SOLVED !

Put back the stock rubber intake pipe and it solved the problem. Iddle is super smooth now.

Thank you everyone for your help

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Hi guys,

I have been experiencing the rpm drops issue for 6 months and cannot really put up with it anylonger.

Issue:
Everytime I come to the stop and clutch in, rpm drops to about 200-300 and sometimes stall the car.
It does not happen when the engine is cold because idle rpm is really high. It only happens when engine is fully warm-up.
It is getting worse now. Even when the car is not moving, if i rev it up to 3000/4000 (Without touching the clutch), it still drops low to about ~300rpm.
I have gone to 2 different Evo mechanic and they could not find any issue at all.

This issue only happened after I replaced my clutch with the Exedy HD (machined flywheel) and replaced the stock intercooler with HDI 3.5'' intercooler.

Things I have tried so far:
-I saw some people in Evom changed out the IACV, Fan controller and put the heatshield in the POD filter (to prevent hot air blowing from radiator fan) to fix this issue. I did all of them but no hope.
-Did the boost leak test but there is no leak at all.

Mods on the car: :
Tomei ARM M7960
Tomei 270 Poncam
Tomei Ti Catback
Walbro 255 Fuel Pump
Turbosmart BOV (Recirculated)
ID1000 cc injector
HDI 3.5'' Intercooler + piping
Spoolin Up COP
96,000 km


Please any one have any ideas what went wrong with the car ? Really appreciate your help. I am now half dead since this car is my DD car.

Thank you for your time

 

Is your car still on maf sensor?

Stock intake? I've heard of issues similar that was fixed by swtchibg back to the stock rubber intake.

I have the same issue, but currently my car has other issues so I haven't been driving.

You can maybe get rid of the maf and go speed density.

 

I am running a metal pipe with stock MAF for months without any problem.

I saw some people switching back to stock rubber pipe and get rid of the issue as well, I just don't have the stock rubber pipe any more.

I am thinking it could be a faulty MAF that is causing this issue. Is there any way I can test the MAF without buying a new one ?

Thank you

 

Any hope guys ? It is such a pain to DD my Evo 7 now

 

I'm no specialist so just thinking out loud, but is it possible changing the IC without adjusting the map has caused it to run lean? that's why it's ok when it's cold, because the ECU is adding extra fuel to keep the idle up?

 

Can you confirm its not a mechanical issue (bad thrust bearing) dragging the engine down? I'd test it by turning the engine over by hand with a wrench on the flywheel bolt, then have someone press the clutch and do it again to see if it becomes extremely difficult. You could remove the spark plugs to isolate the resistance

 

You mean the Idle Air Controller ?

They changed the controller and played around with the iddle but it did not help at all.

 

My mechanic said it is not mechanical issue. Everything is in its best conditions (these guys only fix Evo, they do not take any other cars) .

 

just tune it out.

 

Basically what I meant is that it might be possible putting on the new intercooler has thrown off the map a bit, resulting in the idle dipping sometimes. I'm not sure if changing the intercooler is likely to have thrown off the map that badly but seeing as you only changed the intercooler and the clutch, it seems reasonable to think it could be map related.

 

Sounds like Crank-walk. Prove me wrong my showing a hi-rez picture of the thrust bearing.

 

No need to pull the thrust out, just do that test I mentioned, would only take a few minutes and would rule it out (or prove it)

 

Do you have a method to monitor your A/F ratio and timing?
Idle with and without clutch depressed?

Just trying to find what's going on there.

 

raise your idle speed in the tune

cams are affecting the amount of vacuum

 

Log and post the issue. Show TPS, RPM, AFR, Timing, IPW, ISC Steps, Target Idle, etc.