Sometimes when I come to a stop sign my car will stall out.. like the rev's will drop really low ~400, come back up to normal, then drop back down again, and then stall, it's really annoying driving around town... It doesn't do this is all the time, just sometimes, and has been starting to do it more often then it did in the beginning of the year. When first starting the car I can let it run for 30 minutes, rev it up and down, and the idle will be fine... The problem starts when I am actually driving. Also, if I've been driving for awhile and stop, the car will idle fine... If I shut it off, let it sit for a few minutes, then start it up the car won't idle by itself. It will drop down, come up, be rough, then stall.

I put in new plugs and it still does it. I don't know what else to check, IACV? Last year I never once had this problem, think it could be because of the exedy twin clutch? it's so light the rev's drop too fast or something? just throwing it out there... I know it's kinda confusing, I'm not really looking for a definitive answer, just some things to look into, Thanks!!

 

What's your idle RPM? What's your Idle % from 700RPM - 1500RPM? What box do you have?

 

first, clean the IACV.

next, fully warmed up, idling, wat does idle fb value read? u want to adjust the whole table "idle % vs taget" (meaning highlight the whole thing and adjust it as awhole) until it reads -2% or so.

"hi idle car speed" start with 20mph or something, play with it until u find a good speed.

"hi idle rpm offset" start with 200, once again, play with it until u finda good rpm.

"hi idle wait time" start with .12, and again, play with it until u find a good time.

 

also, if your using decel fuel cut (dfco) play with the off above rpm and the idle feedback rpm. If i remember correctly that was giving me problems like this but that was a couple years ago.

 

This is a very common problem with AEM users. Almost everyone Ive talked to has encountered this at one time or another. Log your advanced idle parameters when this happends to watch what the computer is doing during this time. I found that the computer couldnt react fast enough to the low idle condition to prevent the stall. I bet you've noticed that sometimes when it idles real low and DOESN'T stall that the computer eventually brings the rpms up very very slowly but it usually stalls out before it can fix it.

What I do is tune the idle duty table so the idle feedback is ~ -2%. That way the default position of the idle motor is always open more than it needs to be. So when the computer gets retarded like it does when it stalls and doesnt know where to put the motor, the default position is open more than it needs to be. I also limit the amout the idle feedback is allowed to reduce the motor position with idle FB minimum % setting. This prevents the computer from closing the idle motor too much.

I also bump up timing and fuel in the target idle rpm tables when it dips below the target to give the motor a little extra boost. Thats in the advanced idle settings.

These tips have virtualy eliminated my stalling. In my opinion, this problem is probably the hardest thing to tune out.

 

i have a similar problem with aem ems, but mine hangs at 2k, and slowly drops down if I sit long enough. It seems like it started when it got cold outside...

 

its a 1000 box, thanks for info guys, ill try it out