# Idle drops approaching red lights



## mick (Dec 30, 2004)

When I shift into neutral and push the brake pedal....my idle dives down to 500 rpm. It then comes back to normal when I stop the car. Is this the IAA or crank angle sensor? 
The service manual says check the IAA and the FICD Solenoid. What is FICD and where is it?
When I unplug the IAA the idle drops---is that how you test it?


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## rogoman (Dec 16, 2004)

If you unplug the IAA and the idle speed drops, that indicates that there's dirt in the IAA assembly. The FICD is used with A/C. When the A/C is running, the FICD bunps up the idle.

IAA consists of the IACV-FICD, IACV-AAC and the IACV-air regulator.

There are other things that could cause the idle drop:
- dirty fuel injectors
- dirty spark plugs
- low fuel pressure
- bad O2 sensor


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## mick (Dec 30, 2004)

*Idle drops on braking*

If you unplug the IAA and the idle speed drops, that indicates that there's dirt in the IAA assembly. The IAA I unplugged said AAC on it

Can I clean it or must it be replaced?

I'm wondering about the fuel pressure. The idle drops while braking which pushes the gas in the tank forward. It only happens when stopping for red lights. What fixes are available to maintain steady fuel pressure?

Is there any possibility the ECU could cause this?

Thanx for you help.

IAA consists of the IACV-FICD, IACV-AAC and the IACV-air regulator.

There are other things that could cause the idle drop:
- dirty fuel injectors
- dirty spark plugs
- low fuel pressure
- bad O2 sensor


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## rogoman (Dec 16, 2004)

The IAA can be removed, disassembled and cleaned. Also make sure the throttle body is clean.

To determine if you've got a fuel pressure problem, tee in a temporary fuel pressure gauge into the outlet side of the fuel filter to measure the pressure during various conditions. 
The readings at idle should be as follows:
- with vacuum hose connected to the fuel pressure regulator: 33 psi
- with vacuum hose disconnected from the fuel pressure regulator: 43 psi

If you're paranoid about the fuel slushing around in the tank and causing your problem, then fill the tank full and see if it cures the situation.

Have you ever replaced the fuel filter?


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## mick (Dec 30, 2004)

Yes I recently changed the fuel filter. Also I overoiled the K&N air filter and found it all over the MAF. I'll be cleaning that out next.
My FICD is putting out 1400rpm when the A.C. is on.
Where is the IACV? What is it?


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## rogoman (Dec 16, 2004)

Be careful with the hot wire in the MAF. Don't poke it with the spray tube or try to brush it clean. Just spray it down good - even a couple of times - to remove the grime. Don't use brake or carb cleaner. You want an electrical cleaner that does not leave a residue and is not so harsh that it will melt the plastics.

The IACV is located under the intake manifold towards the rear of the motor. It's used to control the idle.​


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## mick (Dec 30, 2004)

*IACV*

Is the IACV near the IAA?


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## mick (Dec 30, 2004)

OK.......I found out.......the IAA and IACV are all together with the FICD. My A.C. pushes the idle up 400 rpm.............Would it just be the F.I.C.D.?


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