I installed a BBK58 on my auto lt1.The car seems to have very jumpy throttle now. I tweaked the tps a bit but think maybe have to tweak it more to make sure its close to stock settings. Would this being out cause it to be jumpy off idle?
I have not ported the intake manifold yet.Was waiting to do it when do cam,headers and heads all at same time.Would this make it jumpy off idle?
Also since going pretty up there on mods with heads,305 cam and headers would the 58 be better than a 52 for this application.I was considering LE2 heads and he recommends 58 tb but does not say if that is also recommendation for auto cars or just m6 cars.

 

I believe you'll need a new tune now that you have the 58mm tb. Auto guys have to get their pcm reworked when they make the swap, 6 spd guys don't.

 

No way because I am having the same problems with mine. I have done everything. My intake is ported, I have adjusted my IAC like a million times. The car doesn't like to idle right, I have to tap on my gas pedal when I come to stop lights because it idles too high and then after I tap on it it goes back down to about 900rpm where it should. I have replaced the throttle cable and everything. Nothing seems to work. I am thinking now that the BBK is just a POS!