[10evox]

Hello everyone I am new to the forums and evo x! I just bought a new 2010 gsr for a great deal and have loved driving it so far but I started noticing that while I am driving (not stoped) I will put the car in neutral and the rpms will go down to about 750 then bounce back up to about 1500 then back down to 750 and do this for a while, all while still moving and in neutral. I have also noticed a little bot of a rough idle at standstill but nothing too bad the tach just doesn't stay still and moves a lot between 750 and 1000 rpms. I checked both ends of the vaccum hose by the dip stick and they are firmly in place. There are no lights on, and I am bone stock no mods. Sorry about the length but wanted to be as detailed as possible, any help would be awesome
Thanks

 

[whitecomet]

could be your fuel relay but It sounds normal. bouncing revs is mormal when the fan kicks on and off. The range is a little more than what I remember so have the dealer check it out.

 

[SiliconTek]

What intake are you using? The cooling fans blowing onto an open intake can cause that. If it isn't that, then it may be idle RPM vs coolant temperature bug. If you have an OpenPort you can change it or if you have an AccessPort they fixed it with v1.07 of their OTS's.

On the AP it is called Idle Speed (In Gear).

 

[jkc213]

I think that's normal on 2010, mine jumps too on idle, never tried nuetral while moving..
Try to get the latest re-flash from the dealer..

 

[10evox]

It a stock intake on there, so could there be a problem with the intake?

 

[SiliconTek]

I think that's normal on 2010, mine jumps too on idle, never tried nuetral while moving..
Try to get the latest re-flash from the dealer..

It a stock intake on there, so could there be a problem with the intake?

The manufacture supposedly fixed this on the '08 X's but they didn't. Tephra has it fixed with his latest bin, as well as Cobb on their v1.07 OTS maps.

 

[10evox]

I would love to get the Cobb ap if that would fix this, but then again would also like to keep the warranty took for a little while just in case. I only have 1300 miles so far on the clock

 

[daniel_f_us]

Mine does the same until the engine warms up

 

[SiliconTek]

Mine does the same until the engine warms up

Hence the comment about idle RPM vs temperature. As the weather gets colder it will start not going away...

 

[NotAnEvoOwner]

You check this?

http://forums.evolutionm.net/evo-x-general/444277-attention-all-x-owners-do-asap.html

 

[10evox]

Yep that's the first thing I checked

 

[SiliconTek]

You check this?

http://forums.evolutionm.net/evo-x-general/444277-attention-all-x-owners-do-asap.html

That has nothing to do with idle or cruising.

 

[DarwinX]

The manufacture supposedly fixed this on the '08 X's but they didn't. Tephra has it fixed with his latest bin, as well as Cobb on their v1.07 OTS maps.

Sadly no, the Cobb v1.07 tune does not fix this idle issue.

To date I still have this same issue with the funky idle (until the engine warms up) even after getting the Mitsubishi reflash, with the stock intake and with my AEM intake, and with or without my Cobb tune (v1.02 through v1.07). In addition, I've replaced all relays, and secured the fuel pressure sensor line.

My gut thoughts are this is a MAF issue.

 

[flipside]

Take it to the dealer and have them check any TSB's on the issue - they may just need to simply reflash your ecu.

 

[SiliconTek]

Sadly no, the Cobb v1.07 tune does not fix this idle issue.

To date I still have this same issue with the funky idle (until the engine warms up) even after getting the Mitsubishi reflash, with the stock intake and with my AEM intake, and with or without my Cobb tune (v1.02 through v1.07). In addition, I've replaced all relays, and secured the fuel pressure sensor line.

My gut thoughts are this is a MAF issue.

If fixed it with mine. Mine used to bounce all over the place until v1.07. They increased the RPM's in the lower temperature range of the idle map. Idle bouncing around may not always be the tune. You may have something else going on.

 

[HudsonFalcon]

I have an 08 but mine has done the same thing in the past, the car is temperamental for sure. Sometimes I'd be sitting at a light and the rpm's would bounce up and down like a superball. I've been told it's the way the car is tuned from the factory and a good aftermarket tune will cure it, it never led to any other issues so it is what it is. For your own sanity just take it to the dealer and have them check for issues.

 

[johnk]

Could a bad ground cause this also?