0 Vacuum at idle HELP!
Curious to see what's causing it. My talon had these exact symptoms with a little worse idle and I couldn't figure it out before I sold it so I unloaded it for next to nothing. Hope you find the culprit!
Did it just happen one day while driving or just after the instal on a start up?
Did it just happen one day while driving or just after the instal on a start up?
nothing is off under the valve cover. I installed his cams right after i installed the s3 on my car.
It ran for awhile after the cams were installed. around 200 miles so its nothing install related. we even posted a comparison here: https://www.evolutionm.net/forums/ev...tock-cams.html
so his first pass was a 11.2 @ 112 lifting .. it would of been a easy 10sec pass but he was competing in a event and didnt want to get warned so he just lifted off.
the problem happened on the 2nd pass. during a 2-3 the car went from 11.8 to 10's afr.. went super rich, car lost all power..
so it could be a lot of things..
a laundry list of stuff would be something like..
ignition is completely f'ed
map sensor is f'ed (we did a quick disconnect test and connect, but that is not good enough)
fpr f'ed
fuel pump issue?
fuel line issue?
injector issue?
crank sensor going nuts
mivec cam sensor was replaced (new) should be ok
cam sensor exhaust side not replaced but car doesn't throw a cel anymore for either.
did not pressure test direct to intake mani yet
or to the lower ic piping to confirm turbo seals are good
he did order a new ignition since we planned on upgrading that anyways.. i ordered him a sparktech non cdi ignition. once thats installed if it fixes it we will update the thread.
something we didn't do that i want done that Aaron@ ER suggested was.. log mivec. so we will log mivec to check that.. and swap another 4bar out for what hes got in there.. that would have been done but i was not about to remove mine from my car since the AMS F1i makes it a complete hassle to remove.
the car held 30psi~ on a leak test.. BUT it did drop a lot quicker then my personal car does. so there may be some kind of weird leak we missed.
Curious to see what's causing it. My talon had these exact symptoms with a little worse idle and I couldn't figure it out before I sold it so I unloaded it for next to nothing. Hope you find the culprit!
Did it just happen one day while driving or just after the instal on a start up?
Did it just happen one day while driving or just after the instal on a start up?
so his first pass was a 11.2 @ 112 lifting .. it would of been a easy 10sec pass but he was competing in a event and didnt want to get warned so he just lifted off.
the problem happened on the 2nd pass. during a 2-3 the car went from 11.8 to 10's afr.. went super rich, car lost all power..
so it could be a lot of things..
a laundry list of stuff would be something like..
ignition is completely f'ed
map sensor is f'ed (we did a quick disconnect test and connect, but that is not good enough)
fpr f'ed
fuel pump issue?
fuel line issue?
injector issue?
crank sensor going nuts
mivec cam sensor was replaced (new) should be ok
cam sensor exhaust side not replaced but car doesn't throw a cel anymore for either.
did not pressure test direct to intake mani yet
or to the lower ic piping to confirm turbo seals are good
he did order a new ignition since we planned on upgrading that anyways.. i ordered him a sparktech non cdi ignition. once thats installed if it fixes it we will update the thread.
something we didn't do that i want done that Aaron@ ER suggested was.. log mivec. so we will log mivec to check that.. and swap another 4bar out for what hes got in there.. that would have been done but i was not about to remove mine from my car since the AMS F1i makes it a complete hassle to remove.
the car held 30psi~ on a leak test.. BUT it did drop a lot quicker then my personal car does. so there may be some kind of weird leak we missed.
Thread Starter
Evolved Member
iTrader: (23)
Joined: May 2009
Posts: 1,544
Likes: 1
From: Malvern, PA
nothing is off under the valve cover. I installed his cams right after i installed the s3 on my car.
It ran for awhile after the cams were installed. around 200 miles so its nothing install related. we even posted a comparison here: https://www.evolutionm.net/forums/ev...tock-cams.html
so his first pass was a 11.2 @ 112 lifting .. it would of been a easy 10sec pass but he was competing in a event and didnt want to get warned so he just lifted off.
the problem happened on the 2nd pass. during a 2-3 the car went from 11.8 to 10's afr.. went super rich, car lost all power..
so it could be a lot of things..
a laundry list of stuff would be something like..
ignition is completely f'ed
map sensor is f'ed (we did a quick disconnect test and connect, but that is not good enough)
fpr f'ed
fuel pump issue?
fuel line issue?
injector issue?
crank sensor going nuts
mivec cam sensor was replaced (new) should be ok
cam sensor exhaust side not replaced but car doesn't throw a cel anymore for either.
did not pressure test direct to intake mani yet
or to the lower ic piping to confirm turbo seals are good
he did order a new ignition since we planned on upgrading that anyways.. i ordered him a sparktech non cdi ignition. once thats installed if it fixes it we will update the thread.
something we didn't do that i want done that Aaron@ ER suggested was.. log mivec. so we will log mivec to check that.. and swap another 4bar out for what hes got in there.. that would have been done but i was not about to remove mine from my car since the AMS F1i makes it a complete hassle to remove.
the car held 30psi~ on a leak test.. BUT it did drop a lot quicker then my personal car does. so there may be some kind of weird leak we missed.
It ran for awhile after the cams were installed. around 200 miles so its nothing install related. we even posted a comparison here: https://www.evolutionm.net/forums/ev...tock-cams.html
so his first pass was a 11.2 @ 112 lifting .. it would of been a easy 10sec pass but he was competing in a event and didnt want to get warned so he just lifted off.
the problem happened on the 2nd pass. during a 2-3 the car went from 11.8 to 10's afr.. went super rich, car lost all power..
so it could be a lot of things..
a laundry list of stuff would be something like..
ignition is completely f'ed
map sensor is f'ed (we did a quick disconnect test and connect, but that is not good enough)
fpr f'ed
fuel pump issue?
fuel line issue?
injector issue?
crank sensor going nuts
mivec cam sensor was replaced (new) should be ok
cam sensor exhaust side not replaced but car doesn't throw a cel anymore for either.
did not pressure test direct to intake mani yet
or to the lower ic piping to confirm turbo seals are good
he did order a new ignition since we planned on upgrading that anyways.. i ordered him a sparktech non cdi ignition. once thats installed if it fixes it we will update the thread.
something we didn't do that i want done that Aaron@ ER suggested was.. log mivec. so we will log mivec to check that.. and swap another 4bar out for what hes got in there.. that would have been done but i was not about to remove mine from my car since the AMS F1i makes it a complete hassle to remove.
the car held 30psi~ on a leak test.. BUT it did drop a lot quicker then my personal car does. so there may be some kind of weird leak we missed.

and when doing the boost leak, from 30PSI to 0PSI it took a solid 45 - 60 secs
Last edited by 5LEEPERISAH23I; Oct 3, 2012 at 10:00 AM.
Thread Starter
Evolved Member
iTrader: (23)
Joined: May 2009
Posts: 1,544
Likes: 1
From: Malvern, PA
bump for a high revving part 2 , and me yelling at my car and not realizing that untill i uploaded the video LOL..
and afterwards i checked the plugs, they all look 100% normal. I was kind of hoping they didnt but they all do look the exact same.
and afterwards i checked the plugs, they all look 100% normal. I was kind of hoping they didnt but they all do look the exact same.
So the car was having issues and you took it to the track anyway?
If the car is idling at 0 vacuum and is running like crap it sounds like a timing issue. It is an evo 9 so you may want to check the Mivec Cam gear as it is possible it could be damaged.
If the car is idling at 0 vacuum and is running like crap it sounds like a timing issue. It is an evo 9 so you may want to check the Mivec Cam gear as it is possible it could be damaged.
Last edited by 90blackawdtsi; Oct 4, 2012 at 07:40 PM.
Thread Starter
Evolved Member
iTrader: (23)
Joined: May 2009
Posts: 1,544
Likes: 1
From: Malvern, PA
i dont think the mivec gear is damaged, dont see how it could be atleast. Timing is not off, its been triple checked.
Thread Starter
Evolved Member
iTrader: (23)
Joined: May 2009
Posts: 1,544
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From: Malvern, PA
AEM is weird, there are no - signs on the gauge, that is vacuum so it is -12 to -20 . at some points it does hit 3-5PSI tho
Ok. Here is my thought. It sounds almost like antilag... And if your building like 3-5psi that means your turbo is spoolin. Your just free reving it really shouldn't build boost. So that would point to timing. Have you logged timing to see what the ecu says its doing? But I would check timing, then the correlating sensors. Crank, camshaft. And the bolt on the exhaust camshaft didn't come lose by chance? The one that holds the metal piece on for the camshaft sensor to work? IDK for sure. Just some ideas to throw around.



