hey guys

my evo has been idling very low, only on start up, and will stall after i pull it from gear (reverse or first depening on which way im parked) and put it into nuetral if the situation calls for it.

now what im hoping for here is to brainstorm and discuss the following list of potential problematic areas and start ruling things out. maybe some other guys on here have had simialar problems and can speak from experience and perhaps we can rule some out through intelligent discussion.


a little about the car
its an 03 with about 80k, rom tuned by dynaflash with minor bolt ons, otherwise all stock

as i said earlier, on intiial start up it idles around 400-500 and will die on occasion when going from gear to neutral drop.
after its driven for a few mins and get to temp, it idles fine, right where it should be.

engine throws no codes except for cylinder 1 igniton (awiationg new wires, coils, plugs, and boots as i type this)

my mechanic said it could be a number of problems and solving it is a process of trial and error. could be chasing our tale for quite some time.


idea's:
sticking throttle plate?
dirty or bad afm?
aac?
tps?
iac?
idle speed adjustment?
possibly the tune itself? (nothing accounted for cold start perhaps)
vaccuum leak?
bov adjustment needed?
something related to the ignition code being thrown?
cold start solenoid?




feel free to eliminate a few ideas through rational thinking or add more if im missing stuff (which im positive i am)



i have cleaned the throttle and butterflies (or so i would assume as i have soaked it down with throttle cleaner and then driven the car). that did nothing.

i will clean the mafs next to see what happens and rule it out if anything.

mods, if this is in the wrong section, please move it. it was my best guess as to where to put it for now.

thanks guys

 

could possibly be a temp sensor to your ecm for cold start. does it happen more on cold days than warm days?

 

did it just start happening?

 

Been happening for a while now according to previous owner

It's on both cold and hot starts

Every intitial start it does it no matter what the circumstances are

and only on initial start

It will idle low to until the car is at temp or has been drivingva few minutes
For the first few minutes it drops low on idle aswell

 

Do you have anyway to pull thew rom from you ecu? Could be a setting in there that is off.

 

After having recalls done at mitsu it idled fine at 800 for a few days then went back to low idle

 

I think Im getting something similar. When I start the car it idles rough around 500 for a second or so, then jumps up. Then when Im driving its normal until I put it in neutral, when it drops again to around 500 and almost stalls. When I let off the throttle it drops down like that on low speeds. Im pretty modded: FPGreen, 1000cc inj, cams etc. custom tune. I will talk to my tuner in a few days. Does this sound similar to you or did u resolve it?

 

I hear of people having this problems due to the IAC. Something about one of the plastic teeth breaking off .

 

any updates here man? Did you resolve the issue?

 

Mine was doing that for a little while too after swapping back to the stock intake pipe. I just turned the idle rpm up a bit and advanced timing by 2 degrees at idle in EcuFlash and problem fixed. Unless the teeth are sheered off on the IAC, then raising the idle at the ecu won't change a thing.

 

You could try bumping up your ISCV-neutral values a few points and see if that helps. I just did this to a local car today and it worked like a charm.

 

my problem is opposite to urs ...
my cold starting is gud but after getting warm my car never stands at idle and my afr goes way too rich to 10.2 when the idle starts to drop ...
help mee solve my issue also ...

 

It looks like many of us with 03s and mods are having the same issues. I noticed that the idle stepper look-up table is completly screwy in stock form. There were also several other temp and rpm numbers that were just odd on my stock rom. So I added my tuned settings into the 94170015 rom and the problem seems to have been resolved.

Oh and add "Leaking throttle body seals" to your list of things to check. Mine leaked at anything above +/- 3psi. After replacing them there was a huge difference in drivability and consistancy.

 

Have you mess with the BISS screw? Maybe open it a little will solve the problem. GL

 

share your rom with someone for reference and see what the issue might be. from there go through your mechanical possibilities on your list.