Alright my friend has a 97 type sh prelude thats turbo'd and is running a hondata 2b. The problem.. his throttle is EXTREMLY sensitive and his car idles between 1000-2000 rpms and goes up and down up and down between the rpms at idle. Any ideas?

 

Vacuum line, I know on my '93 Si (H23) non-vtec, whenever I pulled the vacuum lines on the fuel pressure regulator, or the "flapper" valve it did the same thing. Check all vacuum lines...if that isnt it...I dunno.

 

there is a chance it could be the idle air control selinode (can't spell) it right next to the throttle body on the bottom, just check everything else first, as it is an expensive part

 

it might be your tps or throttle position sensor, thats what i been told from my mechanic, if your car idles back and forth in between rpms.

 

Maybee your car hasnt warmed up enough yet or i get it sometimes when my air filter gets dirty check those out.

 

Alright how about this.. if my wastegate was f'd up would this cause the vacuum leak too?

 

Hey guys, I have the same problem with my 92 Si H23. When the cars warms up...the rpms surge from 1000 to 1500rpms until I apply pressure on the gas pedal. Then when I let off the gas...it starts to surge again.

Any ideas?? TPS??? EGR valve??

 

i have the same problum on my '98 gsr w/turbo. i just got done rebuilding the motor, and have a lot of new stuff to check out. the best way to find the problum is to just start isolaing stuff. check everything, and wright down what u find. it is most likly limited to the i.a.c. valve, throttle body and sensors, and coolent flow (the iac works off coolent temp).