random surging bucking idle
 

Basic rundown. Tii swapped my car recently, big streetport, rtek 1.7, walbro 255 @42psi base pressure, straight exhaust, stock turbo/tmic, deleted all emmisions, no bac, no AWS.


My car just simply wont idle right. The tps is set within spec, yet the idle still surges. It will sometimes idle/surge at 2000-2500 and then randomly drop to 700-1200, and the just sit at 3000 as if im holding the throttle. It drives fine, boosts fine, cruises fine. Just wont idle right. I have to reset the idle every single time I drive it, just so it wont die, or sit at 3000.


Ive checked for vacuum leaks, and re sealed both intake manifolds.

When you removed the AWS (not sure why someone would do this, as well as removing the BAC as there are zero advantages) are you SURE you reset the cold start cam to the hot position? And that it isn't sticking?

I've seen a lot of FC throttle bodies lately that are sticky. The plates, usually secondary, will hang open producing a random high idle. A real pain especially when one is trying to tune the BAC idle on a standalone.

The solution is to thoroughly clean all the linkages and shafts both inside and outside. Make sure all the accumulation of crap is gone. Then lube everything thoroughly with penetrating oil and work it well into the shafts and linkages. Once everything is free, clean out all the excess oil as if left, it will just attract gun again and cause the same problem. The throttle body is designed to operate dry.

Ultrasounding the throttle body not only really cleans all the shafts but also the passages in the body that are impossible to access.

Cold start cam is gone, and throttle body is modded.. forgot to mention that :(

Man I really need to figure this out. Gonna pull the throttle body today, and clean it out as best as I can.

Shocker... so after just around 100 miles

Spun rotor bearings, and 6 collapsed side seals. Currently rebuilding it