Hi,
I have an inconsistent idle and cars stalls sometimes from a stop. I also noticed that the idle up that should occur when turning the wheel or turning on the A/C was inconsistent and I think this is what causes the car to stall sometimes, especially when turning from a stop (my car is an auto).
So I pulled off the IAA unit and cleaned it. Before I put it back on I thought I would electrically test the solenoids. The AAC solenoid behaved as expected but the FICD solenoid does nothing. Not only that but it has no spring action. The AAC solenoid has to push out to open the valve. However, it appears that the FICD solenoid must "pull in" to increase air flow. As installed now, just turning the IAA unit upside down will cause the FICD plunger to move and open the air flow passage because it is "floating" in the air passage. I can also verify this by blowing air through the air elbow.
So unless, I have some basic misunderstanding of how the FICD solenoid operates it appears it may bad and when that happens the plunger can float in the passage thus causing erratic operation.
Has anyone done any testing on the FICD when they cleaned the IAA unit?
I could care less about air conditioning but the inconsistent increase in air flow may be confusing things.
I have attached a pic of the FICD solenoid.
Modified by alexh at 7:50 PM 11/11/2007
92 240sx IAA-FICD (A/C idle up solenoid) fail?
Re: 92 240sx IAA-FICD (A/C idle up solenoid) fail? (alexh)
OK,
Found the page in the manual where they describe the FICD valve. There is supposed to be a spring in there. I was real careful taking it apart and I saw no spring - also there are no wear marks where the spring would sit.
Anyhow, doesn't really matter as there is no click sound when voltage is applied.
Found the page in the manual where they describe the FICD valve. There is supposed to be a spring in there. I was real careful taking it apart and I saw no spring - also there are no wear marks where the spring would sit.
Anyhow, doesn't really matter as there is no click sound when voltage is applied.
-
vancouverbc
- Posts: 3197
- Joined: Thu Oct 30, 2003 1:30 am
- Car: 1991 240sx
Re: 92 240sx IAA-FICD (alexh)
I have not found much on the idle-up valve. Did you read somewhere that it idles up around corners? How does it know it is a corner. Does it react to pressure changes? I got mine to stop stalling around corners by cleaning the aac valve. Cleaning the throttle is the first thing to do .
Re: 92 240sx IAA-FICD (vancouverbc)
Thanks vancouverbc for the reply,
What I meant by corners is turning the wheel at the same time while just pressing on the gas from a stop can create a situation on a car with poorly functioning IAA (and possibly other problems) where the car stalls. This is because the power steering loads the engine especially at idle. Of course this will generally only be problem for auto transmission cars.
Of course the idle up for power steering is controlled by the AAC, not the FICD. However, my contention is that if the FICD is erratic because of a faulty solenoid or deposits (even with AC off) it may confuse the computer into doing wierd things with the IAA and my IAA was fairly dirty anyhow.
I'm currently debating either finding a spring which will fit into the FICD thus pressing it into the closed postion (and in my case it will never open since the solenoid is dead but that's OK) or spending $130 for a new IAA assembly at autozone. I don't know if the dealer sells the FICD seperately but my guess is it's as much as the whole assy from autozone.
Are there any online genuine Nissan parts suppliers with a detailed web based parts catalog? I also have a Toyota truck and the online catalog that I use for it is very detailed (although it does not go to the level of bolts, etc.) but I have not found a Nissan one that even lists the IAA.
And thanks for reminding me about the throttle body - need to pick up some cleaner ASAP.
PS. My hats off to those who were able to remove their IAA w/o major surgey. I ended up having to remove the heater core hoses and starter and had to access one of the bolts from the underside of the car. Even then it was a real PITA.
What I meant by corners is turning the wheel at the same time while just pressing on the gas from a stop can create a situation on a car with poorly functioning IAA (and possibly other problems) where the car stalls. This is because the power steering loads the engine especially at idle. Of course this will generally only be problem for auto transmission cars.
Of course the idle up for power steering is controlled by the AAC, not the FICD. However, my contention is that if the FICD is erratic because of a faulty solenoid or deposits (even with AC off) it may confuse the computer into doing wierd things with the IAA and my IAA was fairly dirty anyhow.
I'm currently debating either finding a spring which will fit into the FICD thus pressing it into the closed postion (and in my case it will never open since the solenoid is dead but that's OK) or spending $130 for a new IAA assembly at autozone. I don't know if the dealer sells the FICD seperately but my guess is it's as much as the whole assy from autozone.
Are there any online genuine Nissan parts suppliers with a detailed web based parts catalog? I also have a Toyota truck and the online catalog that I use for it is very detailed (although it does not go to the level of bolts, etc.) but I have not found a Nissan one that even lists the IAA.
And thanks for reminding me about the throttle body - need to pick up some cleaner ASAP.
PS. My hats off to those who were able to remove their IAA w/o major surgey. I ended up having to remove the heater core hoses and starter and had to access one of the bolts from the underside of the car. Even then it was a real PITA.