well...I was thinking is was the adjustment on the TPS. but no luck. At idle...with the idle adjustment screw turned all the way out....my TPS still registers 7%

I can Play with the tolerances in the screws and such holding the TPS to get that up to 9.2%...but 7% is the lowest I can get.

So all I can figure...is that this TB...when it was bored out and put back together...the center shaft was not re-centered. So even though the throttle is closed...the TPS is showing 7%...and thus is triggering a CEL of low RPM...and the engine is trying to compensate, by closing the Idle bypass...figuring that 7% throttle doesn't need any bypass air...the car almost dies...triggers the CEL...then the Bypass and the TPS fight it out...and we have the bouncing idle.

Why this does NOT occur on colder days...but does occur on hotter days I still have yet to figure out yet.

I've replaced the TPS. I've replaced the IBP....and the error follows this throttle body from engine to engine....it's just WEIRD!

 

My BTB is an elantra tech special and I had to adjust my throtle cable AND idle screw, now jumpy idle is gone, BUT have you guys both ported the manifold, not just opening the intake side but all of the manifold runners and all?

 

I've tried it with a BIM and a normal IM...no luck.

I can "cure" the Boucing idle for a while...but it always comes back on the hot days.