Throttle body coolant bypass [Merged 9-7]

[terefic181]

Probably not going to settle anything but....You might want to take a look at this earlier thread that addresses this issue. Especially DSMJIM about halfway down on the page.


http://www.dsmtuners.com/forums/showthread.php?t=116353&highlight=throttle+body+temp

 

[NitrousBob]

I agree no gains. I was poor and I can sit in the driveway for a few minutes to let it warm up before I shell out the money for that little motor thing. Cause if it isn't working right it lets more air past the butterfly underneath it than I want causing an idle I cant control.

 

[IA97GST]

Hello Dsm Guys/Gals. I got a simple question. I just got 1300 miles on my rebuilt motor and ive been losing coolant. I was scared of where it could be going. But after double checking everything and giving the motor throttle. Im losing coolant thru the hose that connects to the throttle body. I wanted to know if I could just put a new piece of hose in and jump it over and elimanate the throttle body? Ive heard From friends that this reduces heat on the throttle body and adds power.. Is This good to do or what do you all recomend. Thanks, Larry


Also Me and my buddy are not convinced what the purpose of the coolant in the Throttle body is for? Any answers?

 

[inneedof]

this would make you intake temps alot hotter giveing you a lose in horsepower... bad idea...

 

[MrBoxx]

this would make you intake temps alot hotter giveing you a lose in horsepower... bad idea...

Do you know why there are coolant lines in the throttle body? It's not to cool down the intake charge.

Read this. Even though it branches off into a discussion about blocking off the EGR, it contains a lot of interesting information and opinions regarding the FIAV block-off modification. You could do it; other people have. You may have serious idle issues that may need to be resolved via the BISS or other means. And in colder weather, the engine will take longer to heat up.

Here is another thread on the FIAV, complete with a photo of the bottom of the throttle body. There are blockoff gasket plates available that you can use to do a proper block-off; just unhooking the coolant lines isn't enough.

 

[bmwisthekey]

I believe the sole purpose for the coolant lines going to the throttle body is to aid in the function of the FIAV ( fast idle air valve) for warming the engine up a bit after cold startups, when the coolant gets warm enough it melts alittle wax pellet which makes the FIAV shut down then the engine idles at normal idle speed, it doesn't make you lose horsepower or make your intake temps hotter by eliminating the lines and blocking off the FIAV. If anything it might lower the intake temps somewhat.

 

[nightspeed87]

im considering doin it myself

 

[bmwisthekey]

As MrBoxx stated about having idle issues after blocking off the FIAV and eliminating the coolant lines to the tb, any gains of hp or cooler intake temps are probably very minute the benefits probably dont outweigh the idle headaches you may incur from performing this task

 

[IA97GST]

Hey, Thanks for all your quick responses . After reading some of the links and so forth im gonna leave it hooked up and just replace the lines. Thanks Again, and Happy Tuning

 

[91-gsx]

I have blocked off the lower half of my throttle body in hopes that I could get it to work without the idle valve on it and to also get rid of the coolant lines running through the throttle body. It works but the idle does not stay very stable so i wanted to put the idle sensor back on along with the lower half of the throttle body, but I still wanted to leave the coolant lines off. My question is, if I leave the coolant lines holes open on the throttle body, will that affect anything, or should I run a hose from one opening to the other like a loop? I heard that the coolant lines also melt some sort of wax in the lower throttle body once they warm it up. If the wax does not melt, will that mess something up?
thanks for the help

 

[1stGenRocks]

if the coolant lines arent connected to hot coolant then the car will stay in cold fast idle all the time. what you need to do is block off the 2 opening in the lower half that go to the fiav/lower throttle body. that way you still have the isc and you dont get the fast idle crap when its cold

 

[daren_p]

If Im understanding you just removed the FIAV from the throttle body & tried to run it like this? If you want to run with the coolent lines disconnected you need to still have the FIAV installed but you also want to run a FIAV block off plate.

 

[TimG]

If Im understanding you just removed the FIAV from the throttle body & tried to run it like this? If you want to run with the coolent lines disconnected you need to still have the FIAV installed but you also want to run a FIAV block off plate.

You can't just remove the FIAV. It's a part of the throttle body and doesn't just 'bolt' out. If he wants to keep his coolant lines off, just block off the FIAV. I don't remember if the FIAV inlet or outlet shares the same port as the ISC but just take it a part and block off the opposite single port specifically for the FIAV.

JB weld is good for block off material. Just make sure you let it set for 24hours.

 

[daren_p]

You can't just remove the FIAV. It's a part of the throttle body and doesn't just 'bolt' out. If he wants to keep his coolant lines off, just block off the FIAV. I don't remember if the FIAV inlet or outlet shares the same port as the ISC but just take it a part and block off the opposite single port specifically for the FIAV.

JB weld is good for block off material. Just make sure you let it set for 24hours.

Unless the 1G TB is different, it looks to me according to CAPS that the FIAV is just a bolt on that can be removed from the TB, now yes the ISC would have to be removed as well, but from reading his origional post is sounds like he removed both these completely? (but then again is it even possible for the car to run with these removed?)

 

[staticbrainwash]

The fiav has ports in the TB itself that lead into the lower TB. That port can be "blocked" via jbweld, silicone, or welding and then the coolant lines may be removed. Therefore you can retain the isc but not worry about the fast idle on cold start.

You can also buy blockoff plates now that will take out whichever part you want gone. (whether it be isc, fiav, or both.)

 

[91-gsx]

Unless the 1G TB is different, it looks to me according to CAPS that the FIAV is just a bolt on that can be removed from the TB, now yes the ISC would have to be removed as well, but from reading his origional post is sounds like he removed both these completely? (but then again is it even possible for the car to run with these removed?)

I did block off the bottom half of the throttle body and have had a problem with the idle going up to 1200-1500 rpm and then settling down to my dsmlink set idle of 900 rpm. I also can adjust the idle with the biss screw alone, its kind of nice to have that control with a turn of a screw, very simple. Just yesterday I was taking the throttle body off because I was going to block the fiav opening and put the isc back on, and only after I had the throttle body elbow off did i notice that i had the throttle position sensor unhooked . So my attempt at blocking off the bottom half of the throttle body is still not over. I put rtv on the throttle body and let it dry over night so that I could put it back on and plug in the tps. I'm pretty sure that the tps being unhooked could cause the idle surge. Do you guys think this is the case?
later

 

[Kevin Jewer]

Not on a 1g. On a 2g the TPS also provides the idle switch function, but on a 1g it is a seperate switch at the back of the TB with the one wire going to it. You can make sure that it's working though. It should be grounded when the throttle plate is closed, and akes sure you haven continuity to the ECU from it's plug. The proper adjustment is to screw the sensor in until it makes the switch, then 15/16th of a turn more. IIRC, it's been a while.

Edit> Also, I made my own block off plate with some scrap sheetmetal. Just cut a rectangle out that covers the whole piece (it can be unscrewed from the TB). If you want ISC, drill out the passages for the ISC and leave the FIAV ones blocked. I ran without FIAV or ISC for a while, but it is really nice to have the ISC active. It provides a few more functions than just idle speed control which can be nice to have. If you are going to use hte ISC though, you might as well then take the time to set the BISS properly.

 

[91-gsx]

Not on a 1g. On a 2g the TPS also provides the idle switch function, but on a 1g it is a seperate switch at the back of the TB with the one wire going to it. You can make sure that it's working though. It should be grounded when the throttle plate is closed, and akes sure you haven continuity to the ECU from it's plug. The proper adjustment is to screw the sensor in until it makes the switch, then 15/16th of a turn more. IIRC, it's been a while.

Edit> Also, I made my own block off plate with some scrap sheetmetal. Just cut a rectangle out that covers the whole piece (it can be unscrewed from the TB). If you want ISC, drill out the passages for the ISC and leave the FIAV ones blocked. I ran without FIAV or ISC for a while, but it is really nice to have the ISC active. It provides a few more functions than just idle speed control which can be nice to have. If you are going to use hte ISC though, you might as well then take the time to set the BISS properly.

So you are saying that the tps does not make a difference in the way my car idles at all? I want to make sure of this before i put the throttle body on thinking that the tps could have caused some problems.
later and thanks for the help

 

[Kevin Jewer]

I won't say for sure until I actually test this theory, which won't happen since I sold all my 1Gs but I am fairly certain. The 2g for sure does not care what TPS is, it only looks at the idle switch. Since the 1g also has an idle switch, I can only assume that it also does not care what TPS is. But for all I know they could put a 10 or 20% limit on TPS too, who knows. If this was my car I would forget about the TPS sensor for now, and look into much more likely sources, like the idle switch, etc.

 

[Auto RS T]

My vote is also for the idle reset switch. I went out to unplug my TPS to see if the car would idle but I forgot that my ECU is sitting about 5 feet away from me and is not installed in the car. I will install it when I get home from work and see if I can get it to surge to confirm your theory (95GSXracer). I will post my results afterwards.

Here is a picture of an old blockoff I did back in the day. I know it could use some improvement but it gives you the basic idea of totally getting rid of the coolant lines after cutting the lower half into two, while leaving the ISC functional.

http://www.dsmtuners.com/forums/showpost.php?p=150995950&postcount=26

 

[Kevin Jewer]

Definitely post the results of that test. It may not surge though, depending on how high the idle may go. Surge doesn't come in until you hit the coasting fuel cut RPM, which at the moment escapes me. I want to say it's around 2000 rpm. I'm really not on the ball today at all...

 

[91-gsx]

I put rtv sealant on the throttle body and it is dry and ready to put in. I am just wondering if i should just put the isc on, or try putting the throttle body on without the isc? I just dont see anything else that could affect the idle other then the bis screw and the tps now. A better question to ask would be, why would the idle just go up for no reason if i have the biss adjusted for the idle and the tps plugged in?
thanks for the help

 

[91-gsx]

Not on a 1g. On a 2g the TPS also provides the idle switch function, but on a 1g it is a seperate switch at the back of the TB with the one wire going to it. You can make sure that it's working though. It should be grounded when the throttle plate is closed, and akes sure you haven continuity to the ECU from it's plug. The proper adjustment is to screw the sensor in until it makes the switch, then 15/16th of a turn more. IIRC, it's been a while.

Edit> Also, I made my own block off plate with some scrap sheetmetal. Just cut a rectangle out that covers the whole piece (it can be unscrewed from the TB). If you want ISC, drill out the passages for the ISC and leave the FIAV ones blocked. I ran without FIAV or ISC for a while, but it is really nice to have the ISC active. It provides a few more functions than just idle speed control which can be nice to have. If you are going to use hte ISC though, you might as well then take the time to set the BISS properly.

Which holes do you have to drill out on the block of plate to make it work?
Please use the picture of the lower half of the throttle body to explain.
http://www.ffwdconnection.com/flow.shtml
thanks for the help

 

[Auto RS T]

The only holes you would need for the block off are the 3 passages on the right half of the lower throttle body in the first picture. This would eliminate the coolant passages and the FIAV, while leaving the ISC.

Here is an article on idle surge. If you haven't seen it yet.

http://www.dsm.org/how-tos/tttt/tttt3.html

Results: When I started my car it idled at 1000 rpm. I unplugged the TPS and the idle was not effected. I did notice a small "quirck" in the running condition for a split second when the connector was unplugged, other than that nothing.

I also rev'd the car up with the TPS unplugged. I rev'd it to 3500 for a few seconds then let off the throttle to simulate "coasting". The car did not surge at anytime.

^Would the car have to be moving to simulate coasting?

Maybe my car isn't the best example either since I do not have a completly factory TB. But those are my results.

 

[91-gsx]

The only holes you would need for the block off are the 3 passages on the right half of the lower throttle body in the first picture. This would eliminate the coolant passages and the FIAV, while leaving the ISC.

Here is an article on idle surge. If you haven't seen it yet.

http://www.dsm.org/how-tos/tttt/tttt3.html

Results: When I started my car it idled at 1000 rpm. I unplugged the TPS and the idle was not effected. I did notice a small "quirck" in the running condition for a split second when the connector was unplugged, other than that nothing.

I also rev'd the car up with the TPS unplugged. I rev'd it to 3500 for a few seconds then let off the throttle to simulate "coasting". The car did not surge at anytime.

^Would the car have to be moving to simulate coasting?

Maybe my car isn't the best example either since I do not have a completly factory TB. But those are my results.

Why would I block the 3 on the right side when they just blocked the bottom one on the left side? I just need to know which of the holes to drill out and i will leave the block off plate I made on.
Thanks for the help