On a trip home from a friends house the throttle and idle on my 92 civic si started acting funny. The car will hunt for idle bouncing between 1k and 2k rpms constantly. Also the throttle seems to have no response for about an inch or so of travel, and then it suddenly rockets to what feels like 50% throttle even though my foot has traveled less than an inch past what appears to be a sort of "Dead Zone" that was not previously there. Could my throttle position sensor need replacing? or is this something more serious?

Thanks for your input

 

Do you have access to a volt meter?
Do you have any vacuum leaks?
Is there a CEL?
Is your coolant level full?

 

Remove and clean throttle body
Remove and clean IACV (replace rubber gasket if needed)
Adjust throttle cable tension properly

 

No CEL,
coolant level is good,
throttle cable tension appears to be good,
I'll check throttle body and clean it tomorrow morning, and I currently don't have a volt meter, I can pick one up from a parts store tomorrow and check for vacuum leaks

 

Found the problem! Somehow the bolts for the idle air control valve had gotten loose and the valve was loose and practically hanging off by the hoses. bolted it back up and everything is running smoothly again!

Thanks for the help

 

Good find. Had something similar happen with my Del Sol. It would surge at idle. My IACV was connected fine, but was pretty dirty on the inside and there is a big plastic screw adjustment thingamajob in it. After thoroughly cleaning the valve, I screwed it in all the way, then backed off 1 turn, and that fixed mine. Much better than replacing $$$ or deleting it.

 

The "plastic screw thingamajob" as you've called it is the FITV (Fast Idle Thermo Valve). Not the IACV (Intake Air Control Valve).

 

Thank you for the correction. Yes, now it all comes back. Both the IACV and FITV were suspect. In my case it was the FITV screw was wound all the way out (or possibly it was actually the cleaning that fixed it, and the screw position was a coincidence).