Idle and partial throttle hesitation
Thread Starter
Newbie
Joined: Feb 2008
Posts: 9
Likes: 0
From: Bucharest
Idle and partial throttle hesitation
Hello,
my 2006 Evo 9 has recently developed a small problem, which doesn't seem to want to go away, instead becoming more and more annoying, with each day passing.
Several things happen:
1. Idle hesitates, sometimes and only slightly. I mean, let's say it normally stays at 900 rpm. It will go as down as 600 rpm then come back up... stay like this for a while... go down again... hesitate for a bit... come back up... and so on.
2. While opening throttle very gently, sometimes a small hesitation may appear. It's rather difficult to reproduce, but it definitely happens from time to time.
3. Around 2900-3100 RPM, again while accelerating very slowly, there's something like a subtle humming noise being heard from what appears to be the front of the car. It stay there for like 1 second and goes away as soon as RPM goes past a certain point. This can't be reproduced with 100% accuracy but something like 90%
It happens only in gear and in all gears. And only around that specific RPM point. Also, if the hesitation at point 2 appears, it's rather likely to appear while trying to reproduce this, while that sound happens. I thought that maybe it's the exhaust resonating strangely at a certain RPM, but as it's not always there and it definitely wasn't there during the last year... I think it's not a viable explanation
All these 3 things started appearing at once so I guess they're related. A guy I know who well... knows a bit about Evos told me there's a rather common thing for dirt to mess up with the throttle body/butterfly valve (sorry, English not my native language, but I think this is what he meant), resulting in hesitations at idle and that it simply should be taken out and cleaned. Car has 22K Km on it.
Any idea? Again, it's something really subtle, so it doesn't sound like a missfire or anything rather radical. Then again, maybe missfires can be really subtle, but I guess they don't tend to happen around a certain RPM Finally, I'll mention that at WOT the car pulls hard (TBE + tune) so nothing to really complain about in that area... However, we all know it's rather difficult to feel subtle differences when pulling at WOT
Thanks a bunch!
-WOT
my 2006 Evo 9 has recently developed a small problem, which doesn't seem to want to go away, instead becoming more and more annoying, with each day passing.
Several things happen:
1. Idle hesitates, sometimes and only slightly. I mean, let's say it normally stays at 900 rpm. It will go as down as 600 rpm then come back up... stay like this for a while... go down again... hesitate for a bit... come back up... and so on.
2. While opening throttle very gently, sometimes a small hesitation may appear. It's rather difficult to reproduce, but it definitely happens from time to time.
3. Around 2900-3100 RPM, again while accelerating very slowly, there's something like a subtle humming noise being heard from what appears to be the front of the car. It stay there for like 1 second and goes away as soon as RPM goes past a certain point. This can't be reproduced with 100% accuracy but something like 90%
It happens only in gear and in all gears. And only around that specific RPM point. Also, if the hesitation at point 2 appears, it's rather likely to appear while trying to reproduce this, while that sound happens. I thought that maybe it's the exhaust resonating strangely at a certain RPM, but as it's not always there and it definitely wasn't there during the last year... I think it's not a viable explanation All these 3 things started appearing at once so I guess they're related. A guy I know who well... knows a bit about Evos told me there's a rather common thing for dirt to mess up with the throttle body/butterfly valve (sorry, English not my native language, but I think this is what he meant), resulting in hesitations at idle and that it simply should be taken out and cleaned. Car has 22K Km on it.
Any idea? Again, it's something really subtle, so it doesn't sound like a missfire or anything rather radical. Then again, maybe missfires can be really subtle, but I guess they don't tend to happen around a certain RPM
Finally, I'll mention that at WOT the car pulls hard (TBE + tune) so nothing to really complain about in that area... However, we all know it's rather difficult to feel subtle differences when pulling at WOT Thanks a bunch!
-WOT
Last edited by griffonu; Feb 20, 2009 at 02:29 PM.
