Idle issues

[presterone]

I have no idle speed control so I'm hoping this is why intermittently my car will surge at idle. I'm sure some of you have run with no idle control before, my car will raise to about 1500rpm and then drop and it does this rythmically when it idles for a little more than ten seconds, sometimes sooner like slowing down from the highway with no throttle input.

 

[James]

Need a little more info.

Buy no ISC you mean you have a block off plate to take away the bottom half of the TB?

 

[presterone]

correct

 

[James]

Last time you checked for boost leaks? Last time you checked the ECU? Any difference between warm and cold?

 

[presterone]

No boost leaks and I haven't looked much into what it is yet because I was 90% sure it was due to having no ISC. And I should say a few things about my setup its a speed density ECU ''jackal'' with just a MAP and IAT sensor, that may help pinpoint whats going on since I don't have to worry as much about vac leaks. It may be related to my tune or something but I was mostly just posting here to see if this condition was common with no idle speed control.