Im just curious as to why there is coolant running through the TB which essentially heats it up? Any idea's guys I just came accross it when i removed my TB and thought it was a little bizzar.

I believe there is a wax ball or something that melts. I think it's to do with cold starts etc. May actually be what we used to use a choke for.

Yeah the coolant is meant to heat up the TB so that it will get to idle quicker or something.
So yeah its meant to heat up the TB when the car is cold.

Tom

hey blakey.. try removing it... and running it without

samurai removed his coolant thingy and he said it goes much better... doesn't heat up the cold air we're intaking.

try it out mate and tell us how you go ok?

I have got mine removed, have noticed no driffence.I don't know about any wax pellet. i think its just a quick heat arrangement???

Well im having my intake plenum HPC Coated and installing a ThermoBlok gasket kit at the same time to make sure all my efforts of keeping cold air in the engine is actually working.

The ThermoBlok gasket kit im installing comes with a coolant bypass fitting so i'll run without it for a while and see if I notice any changes. I just dont want to find out it needs to be cooled or lubricated by coolant (which is very very unlikely and can't imagine why) and do some damage down the track.

You going to use the ThermoBlok gasket for the throttle body as well???

What is involved in removing this? Just clamping up the hose?

What is involved in removing this? Just clamping up the hose?
I would personally advise against clamping/plugging... more so either joining inlet to outlet hose or replacing both hoses with 1 longer one. those hoses are a fixed shape design and it probably would be wiser to remove them if you intend to do it... I actually bought a section of hose yesterday for $6 per metre, good to have some handy anyway... just make sure that there are no kinks in the pipe if you do it.

Genocide,

If you want to bypass the coolant running through the TB you can either use a fitting to join the two hoses together or use a new length of heater pipe and replace the two old ones. Never block / plug hoses like this as leaks will pop up down the track and can cause other problems.

eagleaus im not sure if i'll be installing the TB ThermoBlok gasket as if I bypass the Coolant from running through the TB it wont heat up anyway, however if its a good fit I probobly will. Will decide when the gasket kit arrives.

Blake.

Just for your information if you want to spend a few bucks extra a heater hose off a 1982-1985 Ford Laser KA-KB, Meteor GA-GB, Mazda 323 loops around perfectly, Gates Product code 02-0127... $14 though. (at least for 3rd gens) got it from Autobarn.

The coolant heats up the throttle body there fore heating up the air and helping with atmosation ( converting fuel to a fine spray) of the fuel for cold starting.

Its a smiliar deal with olds cars with carby where u having a foil like hose running from the exhaust manifold to the intake it helps the car idle,

The wax pellet refers to the choke for carburettor where the coolant heats them up and the and turns the choke off

Ok, lets clear up a few myths here :)

The coolant does not heat up the TB for starting, running or any of the above. The heat is an unfortunate byproduct of the system Mitsu and a lot of car makers use. Some cars use a seperate system for air bypass that is far better.

The idea is there is a valve in the area under the throttle body, same place as the ISC solonoid. When cold, the bimetalic metals allow more air to flow through a hole thus the idle speed is increased for better cold running. There is nothing to do with fuel atomisation as the coolant will be cold on a cold start, thus the name of cold start.

When the air bypass valve heats up the bi metalic section moves to block the bypass hole, this is achieved by having 2 different metals that expand differently, as they are joined this will give an effect of one metal pushing the other thus it moves. Basic explaination but trying to keep it simple.

In theory if mitsu had been a bit smarter the isc could pretty much have done the same job, but this may have caused more wear and we all know there are enough problems with the isc.

The main reason for the faster idle is to warm the motor up sooner to give better emissions. An older choke sustem works by restricting the air and opening the throttle plate, thus a richer mixture and more emmissions.

Now to removing these, I did mine ages ago as an experement, on a warmer sort of day, low down there is more torque but over 2000 odd rpm there will be no difference as the air is moving that fast it will nto heat up that much.

The other side effect of the tb heating up is the inlet manifold will also warm up with it, a thermo plate may reduce this but not by much as the studs will also transfew a lot of heat.

To bypass on 2nd gen v6, just take the longer hose off the tb, completley remove the shorter one and put the open end of the long hose back on the water bypass pipe where the shorter one was, confused good lol

On third gen you will need a new section of hose.

Always Always replace the hose clamps with good clamps, pref the efi clamps as these are designed not to cut the hose.

thanks for clearing that up mal, i thought they might have used the same principle for warming up the air maybe i should have thought about the the reason behind the cold start injector oh well im still learining :)

That is fine mate.

The cold start injector gives more fues in a K Jetronic system, which in essance is a mechanical fuel injection system used in older saab, bmw, merc, ovlov etc. Because it is a mechanical system, the system can not provide extra fuel on cold start like an electronic system thus it fires a few squirts of fuel on cold start.

The hot air system in a carb situation is to stop carb icing when the fuel atomises at the venturi, the pipe is called a stove pipe, it runs from the exhaust heat sheild to the air box

So by doing this, it wont cause any damage or poor running effects?

a low idle when cold is about it, noting that the isc will not compensate for.

Do not block it though as the cooling system is designed to have the bypass

So by doing this will we do anything to the little metal things that move?
Because that is what went wrong with my last throttle body and the car was doing crazy **** at idle. revving by itself!

So by doing this will we do anything to the little metal things that move?
Because that is what went wrong with my last throttle body and the car was doing crazy **** at idle. revving by itself!
If you have concerns I guess leave it be, I have had mine bypassed for a few days now (before this thread funny enough, Samurai suggested it to me) and after decent runs had no ill side effects from it... as Mal said, it will still heat up but not as much and as directly. I drive pretty hard anyway and cant really tell you if I have had gains or not from it but as I say time and time again... every little bit must help. :D

i bypassed the coolant flow on mine to the TB and really cant notice any real difference. In fact it actually revs a little higher than usual when cold in neutral. When i put it in neutral ideling it sits at about 900-1000rpm but when its sitting in drive at lights or something ideling it sits way down at 600rpm. dont ask me how the bypass could cause that but it has. I did it by just buying some rubber tubing from supercheap for $10.

I had a look today and i can only see 1 hose coming off my throttle body and it leads some little black plastic thing in the rear of the engine bay, and then that looks like it's connected to something inside the car, possibly the air ducts? i dunno.

ummm look harder...there's 2 hoses coming off the bottom of your throttle body.....

TR-Envy thats probobly going to your charcol canister.

If you look harder you will see two heater like hoses going to your throttle body, they will be larger than vacuum hoses.

ummm look harder...there's 2 hoses coming off the bottom of your throttle body.....
Oh the bottom? this one is on top of the throttle body. I'll have to take another look.