[bl420]

if you take off the brass plate on the FITV you can make sure that the ring (has 2 slots on opposite sides) just make sure thats tightened down.

from time to time it loosens up and something happens to the plunger where air would bypass the valve and create an erratic idle.

 

[3gDC2]

what exactly do I tighten?

Yes, that is the IACV. Before replacing, check the fast idle valve. A number of people have fixed their cold start high/fluctuating idle problems by popping the cover open and tightening the valve by 2 turns.

You can also check the operation of the fast idle valve as follows:

To check the Fast Idle Valve:
(Info from HELM 1992 Service Manual, page 11-85)
Start engine. Remove hose from large black vacuum pipe going to the Air Suction Valve (located next to Fast Idle Valve). Put your finger over the pipe and check for vacuum with the engine at idle; cold and coolant temp below 86 degrees. If no vacuum felt, valve defective, replace and retest.
Warm-up engine until cooling fans come on. Check to see if the valve is completely closed. If not, air suction can be felt in the valve pipe. If any suction is felt, the valve is leaking and the valve must be replaced. Retest with new valve. * Courtesy LPB. Checked mine using this method when i had the same problem. Adjusting it solved it.

I opened up the top of the FIV by removing the 2 screws and removing the thin metal covering. When I look inside all that I see is a big o-ring surrounding a gold looking sphere (maybe the valve.) What exactly are you suggesting I tighten 2 turns? Any help is appreciated...

 

[MarcD]

Like BL420 said, there are two slots on either side of that sphere, carefully place screwdriver in one of the slots and turn clockwise or with a pair of needle nose pliers place each end of the pliers in each slot and tighten a turn or two

 

[3gDC2]

ahh, got it, thanks.. The ring was loose as hell.. I had to turn it 3 times around. Upon tightening, I started my car up. The car idles just like before; at first the rpm jumps above 1000 then slowly works it's way down taking over a minute to reach the ideal rpm. Is this a normal occurence or should I continue to search for other causes?

 

[MarcD]

ahh, got it, thanks.. The ring was loose as hell.. I had to turn it 3 times around. Upon tightening, I started my car up. The car idles just like before; at first the rpm jumps above 1000 then slowly works it's way down taking over a minute to reach the ideal rpm. Is this a normal occurence or should I continue to search for other causes?

I don't know if it is really supposed to be tightened completely down. Either way, don't tighten it real tight, It sounds like you are ok then by what you describe. the idle should be high (1k or above) until the car starts to warm up and the idle should drop down after a minute or so- esp in warm weather