stock 94 civic ex question. When the car first starts up, and only when idle, the engine keeps reving to about 3000 rpm and then drops back down to about 800 rpm. It keeps doing this until about the engine is heated up. Is this normal or something i should worry about?

 

no, this is not normal. it should be high around 1500 and then drop down to about 650 or so after a couple of mins when cold.

there are a lot of threads here about this type of problem with different solutions. I encourage you to do a search and try the different solutions.

by the way, have you recently flushed your coolant? I have heard that air in the system can increase your rpms in an erratic pattern.

 

1) Clean the IACV on the throttle body (see forum DIY).

2) Bleed the cooling system of possible trapped air:




3) Check the Fast Idle Valve. Clean like you would the IACV if malfunctioning: