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Discussion Starter · #1 ·
I've noticed when parked and idling my car surges from 750 to 900 rpms....at 900 in sounds fine...at 750 it sounds like the idler is chattering and noticeable in the car and very noticeable outside of the car. Is that possible?

Secondly...does anyone with a stage II have this idle surge and chattering at 750 rpms?
 

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I've noticed when parked and idling my car surges from 750 to 900 rpms....at 900 in sounds fine...at 750 it sounds like the idler is chattering and noticeable in the car and very noticeable outside of the car. Is that possible?

Secondly...does anyone with a stage II have this idle surge and chattering at 750 rpms?
sounds like a possible vacume leak. I would check all the inlet CAI connections especially if you have the JLT carbon fiber intake.
 

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Discussion Starter · #3 ·
sounds like a possible vacume leak. I would check all the inlet CAI connections especially if you have the JLT carbon fiber intake.
Thanks! Yeah I have the Jlt carbon fiber. My guys is switching in a Mac axleback tomorrow so I will have him check that.
 

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My car also experiences this....:flame: ...can they be connected??

http://www.fordgt500.com/forums/showthread.php?p=29814#post29814
The chattering noise could be a possible bearing issue with the Metco idler but the transmission noise is a totally seperate thing.

The surging is probably a vac leak, this usually happens when the engine is running a bit lean and the computer trys to compensate by adding some fuel.

I have noticed on my JLT intake where the seams overlap at the end there was a tiny spot where the seal didn't fit completly flat and I could see daylight where the rubber clamp was attached.

If any air is allowed to get in to the intake(on any mass air car ) after the mass air meter it is considered to be Unmetered air and will cause a lean condition thus the "hunting" idle. This could also affect the engine at WOT as well but you probably wouldn't notice it though it could be serious.
 

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Discussion Starter · #6 ·
The chattering noise could be a possible bearing issue with the Metco idler but the transmission noise is a totally seperate thing.

The surging is probably a vac leak, this usually happens when the engine is running a bit lean and the computer trys to compensate by adding some fuel.

I have noticed on my JLT intake where the seams overlap at the end there was a tiny spot where the seal didn't fit completly flat and I could see daylight where the rubber clamp was attached.

If any air is allowed to get in to the intake(on any mass air car ) after the mass air meter it is considered to be Unmetered air and will cause a lean condition thus the "hunting" idle. This could also affect the engine at WOT as well but you probably wouldn't notice it though it could be serious.
Thanks!
 
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