fiav blockoff help

[Aproductions]

my car sucks when it is cold and idles like you wouldnt believe but doesnt when warm. anyways what does a fiav delete do and how do i go about doing it? thanks

 

[okm12346]

it replaces the bottom part of the TB. It will fix you idle surge and any other problems you may have. The only disadvantage i know of is that you have to hold the gas pedal down for a min or two in the morning at first start, because it wont idle right away.

 

[TSITurbo95]

+1, I would also know about this.

 

[-red97rum-]

I tried the FIAV block off and my car idled like shit, especially when cold. I do have a dead ISC though and I've been too lazy to send my ECU out for new drivers. So I undeleted the FIAV and my idle is awesome again.

 

[rdejardin777]

+1 on FIAV blockoff

 

[9!'clipseDOHC]

Keep in mind that there is a bypass and a blockoff. The bypass just eliminates the FIAV while keeping your ISC. A blockoff gets rid of both. Actually now that I am posting this I just realized that you have a 2g. This info is for a 1g or at least a 1g TB. But here it is anyways.

You can get a bypass or blockoff plate at Level Zero Motorsports for $10 bucks shipped and just slap it between your FIAV/ISC and Throttle body.

Or you get teh JMF blockoff plate from JNZ tuning for $20 that comes with shorter screws and completely remove the lower side of your throttle body (FIAV/ISC). They both do the same thing but this one cleans up your engine bay a little but completely removing the parts.

Not sure if this is the same for 2gs but I hope it helps somehow.

 

[crimsondragon]

2g and 1g TBs are virtually the same. Anyway what are the symptoms of your idle?

 

[TSITurbo95]

Ok, so the fiav blockoff will have bad idle at startup. But the bypass dosent? What is the advantage of getting rid of the fiav/bypassing it?

 

[Aproductions]

crimsondragon - 2g and 1g TBs are virtually the same. Anyway what are the symptoms of your idle?

when my car is cold in the morning it wont start for like 2 tried with the key, and then it acts ### until coolant is warm. then its fine.

 

[laser92DSM]

I did the fiav blockoff on my 1g laser non turbo and it ran like a top after I put it on and I bought it off ebay for 7 bucks. After I put it on started my car and it reved up to 2000 rpm for just a sec like any other car and then settled at idle.
My bad idle was that it would surge until it was warm.

 

[TSITurbo95]

So should I do the blockoff, or the bypass? What are the pro's and cons to doing both? What is the FIAV for?

 

[ramsack]

i completely cut the fiav off and out of the bottom throttle body part and jb welded and plugged it shut. it idles fine for me.

pros are it gets rid of hoses and IMO makes bleeding the cooling system easier and keeps the throttle body a little cooler.

cons i guess would be some people have idle surge issues.

 

[steve]

What is the FIAV for?

The Fast Idle Air Valve is what causes the car to idle fast on cold starts to aid it warning up quickly. It provides additional bypass air to that from the BISS and ISC until the coolant temp reaches 122F or higher.

If you car idles fine on cold starts and doesn't or idles too slow once it warms up the FIAV isn't the problem. The ISC isn't working or the BISS is misadjusted.

 

[TSITurbo95]

On cold starts, it idles high. So what your saying is I should try the blockoff, if I have problems put it back on? Is there a vfaq for it? One more question, what is the bypass for then?

 

[ramsack]

you could try just not running the coolant to the lines first so you don't have to unbolt anything. the fiav may open though just from warm intake air if you are on a turbo car. it is basically a thermostat that controls idle. there is a wax pellet type actuator in there with 2 very heavy springs and a valve.

 

[TSITurbo95]

So how about a vfaq?

 

[ramsack]

ha i just went to vfaq to look and it is a dead link. i may have and extra fiav and isc assembly i can cut apart again and take pictures of what to do.

 

[steve]

On cold starts, it idles high.

Define high. It should idle about 1500RPM when cold and then drop as the car warms up.

you could try just not running the coolant to the lines first so you don't have to unbolt anything. the fiav may open though just from warm intake air if you are on a turbo car.

Without the coolant lines it will never close. It's starts out open and closes as it gets hot.

 

[crimsondragon]

when my car is cold in the morning it wont start for like 2 tried with the key, and then it acts ### until coolant is warm. then its fine.

Doesn't sound like a FIAV problem. You mean you crank it twice before it has to start? How long do you hold the key to crank it? And define ###.

Ok, so the fiav blockoff will have bad idle at startup. But the bypass dosent? What is the advantage of getting rid of the fiav/bypassing it?

So should I do the blockoff, or the bypass? What are the pro's and cons to doing both? What is the FIAV for?

On cold starts, it idles high. So what your saying is I should try the blockoff, if I have problems put it back on? Is there a vfaq for it? One more question, what is the bypass for then?

If you do the blockoff, you essentially lose both the FIAV and ISC. Most cases the ISC is used to regulate idle. Eliminate that and you'll have a hard time trying to idle the car unless you have a way to simulate that you have an ISC which is where DSMLink usually come in. With just the blockoff, you eliminate the valve to let air in on cold startups to give you a higher idle to let the car warm up quicker. Also in some cases, without the FIAV the car will die when it first starts up. The higher idle prevents that. Without the FIAV, you'll have to keep your foot on the throttle a little bit to prevent it from dying. I recommend doing either a blockoff or what I did which is close the valve forever. Follow here: http://www.dsmtuners.com/forums/articles-intake-exhaust/320951-fiav-adjustment-disable.html
Another advantage is that once the car is fully warmed up, you'll have 180*F coolant circulating in the TB heating up the air. That's a big no no in the performance outlook and eliminating the valve along with the coolant lines will generally prevent a slight decrease in performance. I say generally because the head will transfer a lot of heat thru the intake manifold to the TB anyway in the end.

you could try just not running the coolant to the lines first so you don't have to unbolt anything. the fiav may open though just from warm intake air if you are on a turbo car. it is basically a thermostat that controls idle. there is a wax pellet type actuator in there with 2 very heavy springs and a valve.

There is no wax pellet. It's exactly like a thermostat. And I remember there being only one spring and it was not that heavy.

 

[ramsack]

Without the coolant lines it will never close. It's starts out open and closes as it gets hot.

correct, my bad.

if anyone likes to read try to find "1990dsmtechmanual" in pdf. pages 124 and 125 explain the fiav system, and pages 156-158 explain the isc system. the illustrations for the throttle body are a little off because it's for a '90, but it all works the same. there is A LOT of good reading in this book.

 

[TSITurbo95]

It ranges from 1500-2000rpms. I also have idle issues as well, my idle fluctuates when warm too, 500-1200. Also in the summer, it has maaaad idle surge.

I have dsmlink v3. So if I do the blockoff, what do I enable in dsmlink to get it to idle correctly as if I had everything working correctly.

 

[ramsack]

There is no wax pellet. It's exactly like a thermostat. And I remember there being only one spring and it was not that heavy.

thermostats work by an encased wax that expands when warm and opens a valve. the fiav is the exact same thing. i have the piece from inside the fiav i took apart and when you hold a lighter to it there is a metal rod that starts working its way out.

straight from mitsu

here is a vfaq on properly adjusting your idle on a 2g. you shouldn't just adjust it without the ecu set for adjustment. maybe this will help. there is also an idle surge faq on vfaq.

 

[TSITurbo95]

If I block off the fiav, what in dsmlink do I use to simulate the isc for idle? Cold start, warm, etc.

 

[synthetek]

If I block off the fiav, what in dsmlink do I use to simulate the isc for idle? Cold start, warm, etc.

You cant simulate the ISC, the ISC (Idle Stepper Control ) is a motor that adjusts the idle. It raises the idle a little when you turn on AC or lights or other things that put more load on the engine, it tries to add or remove air to raise/lower the idle to keep it at the preset RPM. If you delete the ISC the BISS screw will be the only way to adjust the idle.

 

[TSITurbo95]

Doesn't sound like a FIAV problem. You mean you crank it twice before it has to start? How long do you hold the key to crank it? And define ###.





If you do the blockoff, you essentially lose both the FIAV and ISC. Most cases the ISC is used to regulate idle. Eliminate that and you'll have a hard time trying to idle the car unless you have a way to simulate that you have an ISC which is where DSMLink usually come in. With just the blockoff, you eliminate the valve to let air in on cold startups to give you a higher idle to let the car warm up quicker. Also in some cases, without the FIAV the car will die when it first starts up. The higher idle prevents that. Without the FIAV, you'll have to keep your foot on the throttle a little bit to prevent it from dying. I recommend doing either a blockoff or what I did which is close the valve forever. Follow here: http://www.dsmtuners.com/forums/articles-intake-exhaust/320951-fiav-adjustment-disable.html
Another advantage is that once the car is fully warmed up, you'll have 180*F coolant circulating in the TB heating up the air. That's a big no no in the performance outlook and eliminating the valve along with the coolant lines will generally prevent a slight decrease in performance. I say generally because the head will transfer a lot of heat thru the intake manifold to the TB anyway in the end.

There is no wax pellet. It's exactly like a thermostat. And I remember there being only one spring and it was not that heavy.

So with what you did, does your car idle fine? Isnt that the same thing as a bypass plate?