Bad Idle hunt

So I just got 1886 all back together after having a complete rebuild and she runs just fine. No doubt in the near future she will need a tune. However, when she idles she never stops idle hunting and the rpms never go less than 1300rpm. I think this might be the thremal valve on the vehicle. Any of you guys hear of similar issues and how to fix this problem?

 

[Dark_Horse]

1. Have you adjusted the BISS screw to see if you can bring the idle lower?
2. Is your IAC/ISC good? If it's the brown one, I'd suggest picking up a black one instead.

There are a couple of VFAQ's on idle surge.

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If you have DSMlink, it's very easy to check to see what's going on with idle problems.

 

[gramkrakr89]

Quoting R34P3R62:
So I just got 1886 all back together after having a complete rebuild and she runs just fine. No doubt in the near future she will need a tune. However, when she idles she never stops idle hunting and the rpms never go less than 1300rpm. I think this might be the thremal valve on the vehicle. Any of you guys hear of similar issues and how to fix this problem?



It could be the FIAV if you have one... if so, this is a problem that needs adressed before you try to adjust anything.

Don't mess with the BISS just for fun, figure out what the problem is and then adjust the idle properly.

could your throttle be held open too much by the idle switch?

 

[desant78]

Do you have a way to log? Ensure all your sensors such as coolant temp are in the proper range and hooked up correctly. Also a boost leak test is in order if you changed any gaskets etc I had a similar problem, ended up.being a ton of things at once.

 

[gramkrakr89]

^ yes... very important if you just put everything back together

 

Pretty much what everyone said on here, boost leak was causing my weird idle. good luck.