i have a 99 si stock b16. this only happens when driving. if u let off the accelartor
the rpms will continue to increase after accelration. i have a check engine lamp but only stored codes for cat efficiency and my cat is failing so we can rule out any help from that. i have replaced the idle air control motor with one i had on another b series i knew was running correctly. i also swapped ecu just to be sure also. i sprayed intake manifold with throttle cleaner to check for possible intake air leaks and pinched off vaccum lines to brake booster purge volume control soilnoid, ect... still no change in concern. at this point i am alittle unsure where to go from here since nothing is electronicly failing that i can see... the throttle does not physically stick i have checked several times and idle screw has never been
adjusted. the only thing i can maybe think of is that the tps is sending incorrect voltage measurements to ecu. but i really dont know. please hit me up if you have any ideas thank you !!!!

 

I think the TPS voltage should be 5V fully open and 0.5V fully closed (maybe someone can verify).

Also, have you checked whether the throttle cable may be binding?

 

how do you check if it is binding?

 

TTT

 

or it could aslo be your throttle cable because i went through the same problem i let go of the gas and the rpm went up then down then it idled pretty crazy and all i did ws readjust the cable and i was good no crazy idle

 

have you checked the throttle cable?

 

throttle cable moves, but how else should i check it?

 

TTT

 

BUMP

 

TTT