Hi,
I have an Evo IX MR with ROM 88590015. My Mods are in my sig. I have been having an issue with stalling with the AC on. It only happens with the AC on. The problem occurs when I am driving with the rpm at say 3000 rpm and push the clutch in and brake to say downshift and the rpm drops really low and it does one of the following:

Rpm drops really low;Check engine lights come on for a sec;Rpm bounces back up and back down stumbles some then stabilizes.

OR Rpm drops really low and the car just stalls. This sucks when your making a left turn.

I know I have CAMS, a light weight flywheel and Intake which contribute to idle and stalling problems, but is there anyway to fix this issue? I have tried adding some new idle definitions which I found on here and they do work at changing the idle, but the problem is the exact same. I have actually tried setting the idle as high as 1200 rpm (and the rpm did idle at 1200 rpm) and the problem was as bad as before. So I set the idle back down to like 936 which is a perfect idle for cams and keeping it smooth. The car idles great, except for the stall issue I am having, which only occurs with AC on and pushing the clutch in while moving.

So I made some logs so maybe someone can figure out a solution or give me some ideas. I made a few logs: Idle for 10 minutes, Cruise for 10 minutes and a few logs of the problem occurring. One of the problem logs it stalled and the other two it almost stalled but recovered. The log where it stalled you can see the rpm drop to 0. So theres logs of both situations. Thanks in advance.

 

Have you re-scaled your MAF yet?

 

I have the same problem and I don't have cams.

 

This happens to me sometimes, I think the light weight fly wheel is the problem.

 

Increase the ISCV with AC ON 10 Steps throughout the temp range.

Increase Drive AC ON RPM to 953 RPM or so.

 

Your idle and cruise logs show that your trims and injector scaling is pretty much spot on, so you're good there.

I would start with the changes that Phenix_fyah suggested above. The ISCV may simply need more correction with your combination of parts to be able to catch the idle when the AC is on.

Try that out and let us know what happens.

EDIT: I looked at your problem logs and nothing really looks wrong. It's just that you are getting coasting cuel cut for a bit, then RPMs drop very quickly and when the injectors finally start firing again to catch idle, it is a bit too late, and you either stall or stumble and recover. Actually, I didn't think coasting fuel cut when the clutch was in or in neutral...I thought it was only with the car in gear and no throttle. But anyway, your idle just needs more time and correction. So, bumping the AC idle and increasing the ISCV steps should hopefully help out.



Eric

 

When did this start happening? After which part install did you start noticing this? I have a hunch that it is your intake. Try going back to the stock intake and see if it solves your problem. Your going to have to troubleshoot this one part @ a time. It is a PITA, but that is what I do when I have such a problem.

 

Could also be a loose Vacuum line somewhere or PCV line if you have a catch can.

 

Hi thanks for replys. I will try the ISCV and raise ac on rpm to 953 settings. I dont have a catch can and the hose going from the valve cover to intake is attached. Its hard to say when the problem started because I didnt start using ac until after all the stuff was installed. But I am almost positive the intake is ok because that is the first thing I installed and I do believe I used the ac with that a long time ago. I think it has to do with the light weight fly wheel. I will go and try those settings. Thanks everyone for the help.

 

I have the same exact problem.

 

Ok I changed the ISCV with AC on 10 steps across the entire temp range and turned the AC on drive rpm to 953. I posted two jpgs of the stock settings and modified settings so you can see if I did it right. The tables in the pictures reading from left to right, top to bottom. TOP ROW: Desired ISCV intial step position with AC on-Neutral, Desired Idle RPM-Neutral, Desired Idle RPM-Drive, Desired Idle RPM; BOTTOM ROW: Desired Idle RPM-AC, Idle Settings With AC. I am going for a test drive now to see if it is fixed.

 

Please let us know if the above settings helped.

 

That 82C/78rpm in 3rd chart in the first pic may of caused a problem

 

The settings that were changed seemed to help the issue but did not get rid of it. I have changed the rpm settings before to about 1200 rpm and the problem was still there. The 938 rpm ac off and 953 rpm ac on seems to be good settings for the idle, but the problem was still there. I think the (ISCV ac-on) settings that I bump up 10 steps accross the entire temp range seem to be the helping factor. I am going to play around with those now and see where it goes. I am going to bump it up another 10. Does anyone know what exactly those settings do and effect? Thanks.

 

Keep us posted! I have this problem too! Would love to know what each of those settings do also.