what would happend if i dont put my colant lines to the TB???

[kidtsi]

What would happen if i don't put the coolant lines that goes to the FIAV on the TB? just loop the lines in the water pipe, and plug the nipples of the TB.

 

[9!'clipseDOHC]

You mean without using a bypass plate?

 

[Jazz]

I ran 1 of my cars like that for a couple years with no issues

 

[kidtsi]

You mean without using a bypass plate?

Yeah.

 

[kidtsi]

got this post on here.

"THe FIAV has wax inside...when its cold the wax is hard and lets more air through hence higher idle ( to warm up quicker ) on cold starts. Then when the coolant running through the TB and the engine temps get higher, the wax melts and stops air from going through, thus allowing the car to idle lower at normal operating temp ( 700-900 ). Make sence?"

So the car would idle higher and it will idle normal when the wax inside gets hot? engine heat is enough to melt it or i'll need hot coolant?

 

[Colt4G63 also]

I think your idle speed would take longer to normalize.

 

[kidtsi]

I think your idle speed would take longer to normalize.

So what does the block off plate of the FIAV do? would it be the same? wax inside would not get hot still. is the block off gonna block the extract air then? not just coolant?

 

[Colt4G63 also]

A blockoff plate would block the air completely.

 

[blizz99]

The block off plate gets rid of the ISC, the bypass plate just bypasses the FIAV

 

[kidtsi]

Now back to original question...

 

[Colt4G63 also]

I think the FIAV would open and close independently of the coolant temp, depending on engine bay temps and air temp passing through the TB.

I would expect unpredictable idle speed at most. Probably high all the time when the ambient air temps drop below freezing, under normal driving conditions.

 

[blizz99]

I had idle surge on my car until I put on the bypass plate.

 

[EagleTSIawd]

If you did that, you would have to hold the gas a little on cold starts or it might stall. That's about all that would happen.

 

[kidtsi]

I think the FIAV would open and close independently of the coolant temp, depending on engine bay temps and air temp passing through the TB.

So do you think it would be alright? this is not a DD and temperatures here never go below 40f.

I had idle surge on my car until I put on the bypass plate.

I don't have surge issues.

 

[kidtsi]

If you did that, you would have to hold the gas a little on cold starts or it might stall. That's about all that would happen.

Are you sure about that because i don't believe it. wax would be hard on a cold start and more air would pass increasing the idle.
Maybe you are saying what would happen if i use a FIAV bypass plate.

 

[EagleTSIawd]

Are you sure about that because i don't believe it. wax would be hard on a cold start and more air would pass increasing the idle.
Maybe you are saying what would happen if i use a FIAV bypass plate.

Ah scratch that, I was thinking with a FAIV plate on.

True, with out coolant running through it the wax wont expand and seal the bypass hole on the TB. Your idle would stay high, then after temp reaches 180 the ISC will try to correct the high idle and if it can't it will idle surge.

 

[kidtsi]

Thanks eagletsiawd.

Anyone can confirm this???

 

[steve]

I think the FIAV would open and close independently of the coolant temp, depending on engine bay temps and air temp passing through the TB.

Nope, the FIAV needs the coolant flowing to get hot enough to close.
If you disconnect the lines and don't block off the FIAV you'll get additional bypass air and may have surging problems or a fast idle if the BISS and ISC can't be closed enough to drop the idle speed.

 

[BigBeans]

Nope, the FIAV needs the coolant flowing to get hot enough to close.
If you disconnect the lines and don't block off the FIAV you'll get additional bypass air and may have surging problems or a fast idle if the BISS and ISC can't be closed enough to drop the idle speed.

Exactly.

From experience here...the car will idle fine cold but idle like crap (surging) when it gets up to temp. You need a bypass or blockoff plate if you're going to run without coolant. Even with the BISS all the way in and the ISC maxed out you get too much air, and hence idle surge.

 

[BLK97AWD]

I would only recommend eliminating the coolant lines to the TB if running a standalone where there is full control over the ISC.

 

[TJCTalon]

Just order a bypass plate off ebay, they are cheap and easy to install.

Be carefull taking out the screws holding int the bottom of the TB. They strip very easy with a screw driver. You will probably also need a new FIAV gasket too.

One of my favorite mods, I always hated the coolant lines going to the TB.

 

[Alan11]

I have read about removing the freeze plug on the TB when blocking the FIAV and bypassing or blocking the coolant lines that go to the TB. Anyone can explain that to me please.

Never mind i got it.

 

[IceMinion]

Some facts about the FIAV

The engineers at mitsubishi designed this system to extend the service life of the engine greatly. This is why we have 20+ year old 6-bolt engines that have never been rebuilt. The parts just haven't worn out.

If you remove/modify the FIAV or the coolant lines going to it, the engine will take much longer to warm up, the pistons will not fully expand as fast and you WILL lose compression faster.

Also: having a high idle at startup (1500-2000) will build oil pressure faster, extending the life of your engine AND turbocharger(The furthest device from the oil pump).

The ISC is probably what you want to bypass, the system easily fails, and when it fails it damages the ECU.

Simply remove the ISC from the TB and fill the void with a tube of JB weld. This will prevent strange idle issues that DSM's are known for.

 

[9!'clipseDOHC]

The ISC is probably what you want to bypass, the system easily fails, and when it fails it damages the ECU.

Simply remove the ISC from the TB and fill the void with a tube of JB weld. This will prevent strange idle issues that DSM's are known for.

Or, better yet, test the ISC to see if it is working and if it isn't replace it. Come on.

Test: (Do both).

YouTube - ‪DSM ISC motor testing & Replacement‬‏

YouTube - ‪DSM ISC‬‏

Replace:

(New) DSMISC Automotive (New ISC Supplier)

(Used)Mitsubishi Graveyard
Trust me, a street driven DSM without an ISC (or with a non-working ISC) sucks. I've been there, done that. It's better to fix it.

 

[Talondvr]

This is what is done to mine. Didn't see any wax when I opened mine up?
As far as I know there is a spring that expands when heated closing a port that lets a little extra air in during a cold start-up. If you remove the coolant lines do this or get a block off plate.
http://www.dsmtuners.com/forums/articles-intake-exhaust/391977-free-fiav-block.html