i have a 90 hatch si with an AEM intake. i just recently had the timing belt and water pump replacd and now when warmed up the idle fluctuates between 500 and 900. it drops to 500 when i stop and sometimes stays there. also my intake is rediculously loud! any ideas on what it could be?

 

your idle issue could be a vacuum leak, Fast idle thermo valve,or the idle air controll valve. the valves can be adjusted and cleaned respectively.

intakes are loud.

 

how would i clean the valves?

 

Only clean the IACV. Remove it and use brake or carb cleaner or simple green. pressure really helps, spray the **** out of it until no more gunk comes out.

For the FITV pull the back cover off of it (its a round plate held on by 2 screws) then you can see the plunger that needs to be turned, to the right. it helps if you depress the spring in the middle to be able to turn the plunger.

Make sure it isn't just a vacuum leak first.

 

thanks alot man! the "mechanic" i go to just looked at it and said "...um, thats just wierd."

 

this thread would help for my buddies Crx it has the same problem