I have a 98 civic LX with a 96 LX engine (not v-tech). My friend just put the motor in and it won't go to fast idle at start up....maybe 4-500 rpm and when it gets warm it idles at 800 rpms. Could it be tps....also the tps is riveted on. I saw a thread about removing or tapping off tps. Can I buy a new one from auto parts store....or is problem not related to tps.

 

Have you ajusted the TPS control?
Also make shure u set it to the corect volts for a proler setting at no throttle and full.

 

i think you got the water lines mixed up on the bottom of the throttle body, thats where the fast idle thermo valve is located.

 

I'll have it checked this week, thank's.