dozena

Edit; Problem resolved.

Problem: Battery disconnected/cpu reset. Low idle* (see below) (runs fine).
Resolution: I did the Vishnu Brake/boost in 4th. Then I let it idle for 10 minutes. Off. 10 more minutes with AC/Defrost/high beams on. The problem wasn't 100% fixed. So I would just turn it on, let it's do it's thing (below) and turn it off. Fixed! Did it about 5-6 times. Runs perfect again, yeaah!!

Exact definition of low idle: Turn on (warm) car. It would go up to 900 (one small tick below big tick). Then drop to about the 3rd tick and oil light would come on. Surge to 7th tick, back to 4th tick (no oil light). Repeat 3 times. Then go back up to 900 and sit there perfectly. It did this exact (!) routine until it was resolved.

Total miles driven since problem; less than 50.

------------original post below----------------------
Well, it was running perfect. I changed the air filter (dirty), the terminal on the battery was broken, put a new one on.

Also changed the spark plugs (to copper plugs). Car started suffering from cut out at 4K RPM so I put the old plugs back in (NGK 7's).

Car runs fine, drives fine again. But when I slow down from 30+mph, the idle drops way low, then it hunts for 3-4 times and then it's fine again (rock solid idle). Slowing down from 60, it hunted but it died! Not good!

-battery connection is tight, would resetting the battery have anything to do with it?

My car is 100% stock.

Please help

gsrboi80

iTrader: (38)

Give it a few drive cycles, Evo has a lengthy idle relearn sometimes on battery disconnect.

dozena

I'm hoping it's that! Is there any way to speed up the process or did I screw it up when I put the copper plugs in and the ECU is confused?

Should I install new IR NGK's and reset the battery?

RussellDaniel

iTrader: (9)

Running rich when you slow down?? That will cause the car to die.

dozena

Sorry, I don't know if it would be running rich? It seems to be running fine, spark plugs were actually a little whitish.

It was running perfect before then I touched it I put the old pugs back, but something has changed.

Maybe the plug wires? I pushed the 2 non-coil ones down and they clicked in, the other ones are bolted in. Is there a trick to them or just push down and bolt them back?

/whee, second guessing a plug change! The car is actually 'dangerous' to drive now. I came around a corner (not in gear) and the car died, yeeah, not fun. Put it back in gear and started it up.

dozena

I saw this in the EvoX forum, should I do this for the Evo?

"
IDLE LEARNING PROCEDURE
1.Start the engine and warm to reach 80°C (176°F) or more.
NOTE:
When the engine coolant temperature is 80°C (176°F) or more, the warm-up is not needed if the ignition switch is in "ON" position once.
2.Turn the ignition switch to "LOCK" (OFF) position.
3.After 10 seconds or more, start the engine again.
4.For 10 minutes, carry out the idling under the condition shown below and then confirm the engine idles normally.
•Transaxle: Neutral (P range on vehicles with TC-SST)
•Operation in ignition-related, fan and attachments: Not to be operated
•Engine coolant temperature: 80°C (176°F) or more
NOTE:
If the engine stalls while idling, check for a dirty (on the throttle valve) of the throttle body and clean if needed. Then perform the service from Procedure 1 again.

INITIALIZATION PROCEDURE FOR THROTTLE ACTUATOR CONTROL MOTOR
When the battery cable is disconnected and reconnected, throttle
actuator control motor valve (Fully closed position) is eliminated,
so that the throttle valve opening angle control would not be performed correctly. When the battery cable is disconnected and reconnected, initialize the throttle actuator control motor using the following procedure.
1.Turn the ignition switch to the "ON" position then, turn the ignition switch to "LOCK" (OFF) position.
2.For 10 seconds or more, keep the ignition switch in "LOCK" (OFF) position.
"

dozena

Sorry for all the posts.. but after the plug change, I hopped straight onto the highway, drove it for about 20 minutes and then when I tried to slow down it started to hunt around.

I will try the 10 minute idle warm up/repeat.

Also will try the 'vishnu 4th gear brake boosting' but I'm not too sure on how that would help?

Any other ideas?

RussellDaniel

iTrader: (9)

dozena

100% stock, no tune. No afm, heck no boost gauge!! /no boost leaks, the car rips as usual. Just the idle issue.

SilverShadow03

iTrader: (19)

no cel? does it still idle on its own? did you install the ir spark plugs originally before the change to copper plugs? you're not supposed to gap ir plugs in case you didn't know. just asking in case you checked the gaps after removing them and putting them back in.

Grimgrak

iTrader: (3)

I'd check/replace your sparkplug boots. This isn't a honda dont be throwing copper plugs in there. When OEM calls for IR's.

dozena

Problem resolved, editing first post. Going with new IR's this time and I didn't gap the coppers (derg!!).

It was the Battery disconnect/cpu reset. I did the Vishnu brake/boost and the 10 minute idle. Off. 10 Minute idle.

gsrboi80

iTrader: (38)

Copper plugs are not the issue assuming Evo VIII unless gapped improperly or a bad plug/s. To say this is not a Honda use iridiums makes u sound dumb to those who know better. Just an FYI

OP: Glad it was just an idle relearn.

dozena

Yes, I didn't gap the coppers plugs properly so, no fault of the plugs. User error! It runs great on the Coppers btw. But they are temporary until the IR's get here