idle problem

Heads, valves, pistons, rods, crankshaft, etc...

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legacylok
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idle problem

Post by legacylok »

after pulling the engine and changing the head gasket. the idle has been acting kinda weird. when i start it up it will idle fine around 1k rpm but once i start to drive and hit boost it starts to idle at 3k if i don't hit boost then it will continue to idle at 1k. if i let it at 3k for about 30sec to 1min then it will drop back down to 1k

Things I've checked:

no vacuum leak as far as i can tell

cleaned iacv when i did the head gasket

if i move the iacv it just moves the idle pionts i.e. 500 and 2k


any ideas would be really helpful
Kris

92 SS, ej20g, camo wrap, 16g, 06 intercooler,
Robtune, 550s
Legacy777
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Post by Legacy777 »

Can you give us a little more background on what you may have moved or changed when the engine was out.

You shouldn't have to adjust the IAC valve top, and could cause things to be off if you do.

Before you did anything, what was it idling at?
Josh

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yazmo
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Post by yazmo »

hey that sound exactly as the same problem i had
when i play with the idle screw.

i did fix it but since then my idle act weird.
when i set my rpm around 750 and i put my car as i drive on neutral my rpm go higher.

i also experiment my speed needle to jump at a higher rpm
and stick at 3k for few sec even if i release the gas pedal.

its seem to me that the only good setup it so set my engine rev around 600rpm but when i am waiting on a light on the street my rev go lower such as 350 rpm, or if i hit the brake rpm vary. dont know if it's the exact problem but look similar.
legacylok
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Post by legacylok »

when the engine was out heres what i changed:

i did a custom cold air intake

changed from a slant intercooler to a 06 fxt

and plumbed in a catch can


is there any chance the more free flowing intake overwhelms the maf?
Kris

92 SS, ej20g, camo wrap, 16g, 06 intercooler,
Robtune, 550s
biggreen96
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Re: idle problem

Post by biggreen96 »

legacylok wrote:cleaned iacv when i did the head gasket
I don't think they like to be cleaned. Did mine, started acting up. Now I spray lube into every once in a while, works for a day or two and idles like shit again.
wtdash
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Post by wtdash »

I know you did, but suggest another vac leak check.

I have a catch can setup too. When the hose from the PCV to the can is disconnected I have idle issues...so I 'think' it needs to be a closed system...if that makes sense.

GL,
Td
Turbo Subies:
'87 GL-10 Turbo - SOLD
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'04 FXT, Forged internals, VF39, STI TMIC, Cobb AP- SOLD
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legacylok
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Post by legacylok »

lol damn looks like i will be doing another vacuum test this weekend

the catch can i have is currently have setup is a closed system
Kris

92 SS, ej20g, camo wrap, 16g, 06 intercooler,
Robtune, 550s
Lunatech
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Post by Lunatech »

legacylok wrote: the catch can i have is currently have setup is a closed system
Awyeah...the 2 AM sentence structure :lol: Been there done that :roll:

lol
Robert,

Rio Red 1990 L sedan 5MT at least 302000 mi. and Spruce Pearl 1996 Wagon 4EAT 245000 mi.

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wtdash
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Post by wtdash »

I should've added:

make sure your hoses are good...if they're old/hard replace 'em. I had one crack underneath...couldn't see it...but felt it luckily.
Turbo Subies:
'87 GL-10 Turbo - SOLD
'90 BJ EJ22T/DOHC & 5speed swap - SOLD
'04 FXT, Forged internals, VF39, STI TMIC, Cobb AP- SOLD
'93 Legacy SS - 5-speed, SOLD :-(
'02 WRX -SOLD
'96 BD-turbo'd-SOLD
'98 SF - NA-T
kimokalihi
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Post by kimokalihi »

Lunatech wrote:
legacylok wrote: the catch can i have is currently have setup is a closed system
Awyeah...the 2 AM sentence structure :lol: Been there done that :roll:

lol
Could be drunk. That'll happen when you're drunk. Or worse. One time I was browsing the latest posts and found one of my own from a while ago when I was drunk on here. Cracked me up because I couldn't even remember making the post!
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Lunatech
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Post by Lunatech »

kimokalihi wrote:
Could be drunk.
Been there done that too :smt045
Last edited by Lunatech on Sun Dec 06, 2009 5:43 pm, edited 1 time in total.
Robert,

Rio Red 1990 L sedan 5MT at least 302000 mi. and Spruce Pearl 1996 Wagon 4EAT 245000 mi.

georryan wrote:
Don't knock him for thinking outside of the box. At least he has been creative.
legacylok
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Post by legacylok »

lol good times! and now we know why my car is broken :lol:
Kris

92 SS, ej20g, camo wrap, 16g, 06 intercooler,
Robtune, 550s
253.Asmo
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Post by 253.Asmo »

Done THAT too.! Lol
'94 White SS / 5MT - daily, absolute piece of a beater

'90 Red Sedan - EJ22T / 5mt Swap - drove it, SOLD it

'91 black SS / 5MT - (215/230k miles. eng/body)
[RIP - drove, hit, cracked a piston, swapped and stripped for swap again]
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