Comp 224/230 cam and 52mm throttlebody. When I get on the brakes it seems to want to stall. Ion at madz28.com did the tune. Could it be IAC or possibly the aftermarket tb that's causing this? Thanks

 

My money is on the IAC, but i would also look for vacuum leaks.

 

That size cam will have no affect on brakes, or so I have been told. Sounds like vacuum leaks.

 

I'm running the COMP 503 with a 52mm throttlebody also. No problems yet, so I doubt that it's the throttlebody. Like said check the IAC. Just for curiosity, what happens if your crusing along and push in the clutch but not the brakes? Any different?

 

+ 1
Check the IAC motor. Mine did the same thing with a SMALLER CAM. Replaced the IAC and all is good

 

cleaned the IAC sensor and problem remained. Replaced the BBK 52mm throttlebody with factory 48mm and car runs perfect!

 

I would put the 52mm back on and adjust it properly. It sounds like your blade opening is set incorrectley.

Hook up the laptop and look at the TPS volatge on the 52mm and make sure it is with in spec. It should be about .5 volts. I like to turn mine to the max before it kicks out of the idle mode around .7v, if you have the laptop hooked up with DM running you can adjust the TPS with the engine running and hear the change when it kicks out of idle mode. If you set the TPS as close as you can to this point it will help with off idle stumbling and throttle responce.

I would set it at .5v until you get the idle blade position set and then fine tune the TPS.

Then with it idling with the correct TPS volatge adjust the stop screw until you get around 30 on the IAC counts, adjust slowly as a small change in the screw can have a big effect on the counts once you get close.

After doing this you can readjust the TPS as above.