So my idle has been giving me grief for some time, and I am ready to just start replacing parts. Symptom...coming to a stop, push in the clutch, it dies sometimes. Or it almost dies and searches around for the idle, fluctuating 500rpm's or so. Sometimes is fine. I am thinking first trying a new idle air control although it tests fine. I read from a few people that had this issue and theirs tested fine, but when replaced took care of the issue. Think this is a good place to start?
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Question on what part to buy
- Thread starterdeez
- Start date
Tune? Bov recirced? I have big cams and when coming to a stop instead of pushing in the clutch and letting the rpms just drop I let the car just "gear down" to slow it and that usually prevents any stumble at the stop. Just pushing in the clutch and letting everything fall prevents it from recovering it that fast. I am just used to it and drive it like that. /ubbthreads/images/graemlins/dunno.gif
JSchleim18
Well-known member
I do the same thing as Jay. I learned to live with the problem bc I got stumped as well. Let the car stay in gear and let the motor whine down to under 2,000 RPM's and then you should be able to press in the clutch or put the car in neutral without it stalling.
Gary_Chiu
Well-known member
A lightweight flywheel can be the cause of your problem too.
BOV is recirc, good tune with fuel trims around 100, timing at 7*, no boost leaks, vehicle speed sensor replaced and working, ECU rebuilt, did it before cams (264/272 HKS) were installed. The flywheel is an ACT chromoly so it's not that light, and again it had the issue before the flywheel was replace. So with that info, it seems to point to the ISC or idle air valve or whatever name it goes by.
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SmoothCustomer
Well-known member
If you suspect the fiav, buy a block off plate and see if that helps, then replace the tb or have it rebuilt because you don't really want to just run the block off plate all the time.
atc250r
Staff member
The FIAV is what the coolant hoses on the TB are hooked to. It is used to kick up the idle when the engine is cold so you can get away without it fairly painlessly. Every time I've seen a problem with an FIAV it gives you a high idle so I doubt that is your problem. Thinking about it, a faulty FIAV can probably only give you a high idle when hot or a stall when cold based on how it operates. I would guess that assuming you set your base idle as per the VFAQ the ISC is probably on its way out. There used to be a couple of places online that advertised rebuilding them, I don't know if they are still around.
John
John
turbowop
Well-known member
They're the same thing.
Isn't there a port on the TB that can accumulate gunk? I know some TB's do, but can't remember if it is a problem on ours...If it is, then use some of that TB spray (not carb cleaner unless you're doing this on abench and no sensors, etc.).
