Irratic idle after service PROBLEM FIXED thanks ECUMAN / BEEZA etc

[I heart the SSS]

Hey guys..

I just serviced my EJ8 Coupe (D16Y8 SOHC VTEC)

The car now has a very irratic idle, aka you give it a rev, it falls down to 1,000 RPM, then goes back up to 1,500 RPM, then back down, and up etc.

I used some Subaru upper engine cleaner on the Throttle body, and drove it after to purge it out of the car. New plugs, oil, filter followed.

I read this somewhere


) Did your Throttle Body get bored out at all? Is Air bypassing the blade?

Could I have covered the sensor in the intake manifold in gunk? thus making it fail and not pick up the air readings?

[SHOGUNOVDDRK]

so its surging.
What you've stated is a possibility.

[I heart the SSS]

http://www.superhonda.com/forum/f94/diy-cleaning-your-iacv-144463/

I think this is the issue

the IACV is clogged?

[SHOGUNOVDDRK]

Bro, can't read (on phone, lol)

give the IACV a clean up and see if that helps it

[90LAN]

justin use your subaru upper cyclinder cleaner lol
to fix this problem and to clean

[JohnL]

Unplug the IACV (i.e. electrical connector at the IACV) and see if the idle drops and / or stabilises.

[bennjamin]

chances are the upper cleaner may of clogged the ICAV - as john stated disconnect it and see if it drops or alters rpm

[I heart the SSS]

I took the IACV off, gave it a good clean with electrical contact cleaner.

I bolted it back up and still the problem is

1. Start car
2. Goes to 1500 RPM
3. Drops to 1000 RPM

*rev the car gently to 3,000 RPM*

1. Falls to 1000 RPM
2. Goes back up to 1500 RPM
3. Falls to 1000 RPM and settles.

I also removed the resonator for the intake...

any ideas?

[bennjamin]

this is while the engine is dead cold or warmed up ?
did you misplace the clip for the IAT sensor ?

[I heart the SSS]

I unplugged it then ben, the car seems to idle fine.

I reconnected it, more air began to pass through the air filter box (it sounded more ballsy as soon as i clipped it in)

And now the idle is back to be HEAPS irratic..

hmm

edit: car is warmed up.

[bennjamin]

replace or swap with known working one (off a friend etc) to confirm its the IACV.

[I heart the SSS]

Don't have any friends who drive these cars lol

****.. might see how much one is from honbits?

(the car was fine before this)

[OMG.JAI xD]

Vacuum hose disconnected sumwhere?

I remember doing the subaru engine cleaner clean. Taking off my brake booster vacuum line and feeding it there, when the engine warms up idle fluctuates at a constant pace up down up down.

[beeza]

I put some suburu upper engine cleaner through my mates truck today and the idle was high.I may have the same prob (hopefully it will just evaporate)

But maybe,Clean and adjust the FITV.

http://www.ozhonda.com/forum/showthread.php?t=51798&highlight=adjust+FITV

http://www.emotors.ca/Articles/97.aspx

Once you locate it,take the cover of (2 screws) then you can use a mirror to see inside it.Get a screwdriver and just turn it until it idles fine,then you can fine tune it with the idle screw.5 minute job!

[I heart the SSS]

hmm, but my pipe is still getting heaps warm?

I presume its not FITV?

[ECU-MAN]

dont think the EJ8 has a FITV

try resetting the ECU and make sure all you vacuum hoses are on properly, an air leak or vacuum leak will cause funny idle.


you can try spraying TB cleaner in IACV and TB then take it for a good drive to get rid off all the fumes. make sure the spark plugs are gapped at 1mm

[I heart the SSS]

EDIT: Read ECUMANS post.

Maybe I should run some more of that subaru engine cleaner through the TB, and see if it removes any furhter gunk i guess.

All the VAC lines are in and in place..

Does it mean anything that I remove the electric clip and the idle settles, and then once reconnected, becomes more irratic than before?

edit edit: I used the NGK plugs that are standard for the EJ8, should be gapped correctly?

[beeza]

http://www.honda-tech.com/showthread.php?t=1564019

D16Y8s have FITV?

I was looking for that thread for the last 30 minutes!!

I'm not sure if the y8's have an FITV,I was worried about that...

Hmmmm,it sounds vacumn related.When I had this problem I cleaned the IACV and adjusted the FITV and it fixed it.But it was the FITV that really needed to be adjusted.If there's no FITV then I'm stumped!

[I heart the SSS]

hmm

No idea what to do now.

[beeza]

This is frustrating me,I wish I had the car here so I could check it out.I just cant think of anything else...

A foul 02 sensor wouldn't cause this.

But the idle on the truck today was high (not erratic) after I put a can of suburu UEC through it,so it's probably just what benny said and will hopefully settle after the UEC evaporates away.I will try the truck tomorrow too.

[trism]

check the gaps.

alot of the time they arent even gapped right i find.

[ECU-MAN]

Does it mean anything that I remove the electric clip and the idle settles, and then once reconnected, becomes more irratic than before?



what do you mean by this. Im confussed.

did you unplug the TPS ???

did you mess with the idle stop screw ???

[I heart the SSS]

I mean i unplugged the clip which goes to the IACV valve.

It's a small grey one, there is only one electrical clip on it.

(i undone two, one black, one grey, one goes to the IACV, ones right near it)

[ECU-MAN]

OK, im with you now

you disconnected the IACV as you mentioned, and the idel settled.

it settled baucause the ECU want changing the idle rpm, and also went into limp mode.

the black connector is the IAT sensor.

[I heart the SSS]

Noted that, thanks.

I will go to Supercheap and get some decent carb cleaner, clean the intake manifold, and clean the sensor, probably leave the sensor in the sun or w/e to dry out, then see how we do.

I presume the engine bay fuse is labelled

"EFI E/M"

As in engine managment, top left of the box, 7.5 amps.

[ECU-MAN]

should be labled backup did you see "EFI E/M" ??

if your unsure, disconnnect the battery for 15 sec, or unplug the ecu connectors

[I heart the SSS]

After gutting the Intake manifold furhter and cleaning the IACV AGAIN, it's back to normal!

The idles a bit high, but other than that, it' spot on!

Rep given where needed!

Thanks a lot for this, i hope many can benefit from it lol

[beeza]

haha,you changed the title,PROUD to be there with ECUMAN :)

What do you mean by gutting the IM?

Have you turned the idle down via the idle/air screw on the TB?

Great to hear!

[ECU-MAN]

haha,you changed the title,PROUD to be there with ECUMAN :)

What do you mean by gutting the IM?

Have you turned the idle down via the idle/air screw on the TB?

Great to hear!

lol..... you did very well

[EGJOE]

Good to see its all fixed
carby cleaner rules:thumbsup:

[beeza]

lol..... you did very well

Thanks John!

I had issues for a long time and that learnt me real good! :p