ryostyle_the_¥akuza Posted May 4, 2006 Share Posted May 4, 2006 There is a fat coolant line on the water housing pipe that originally fed to the intake tract on the little 4WD cover that connect to the throttle body of my 87 rx hatch. I have removed this cover and intercooled my rx with a top mount, is this coolant line responsible for avoiding hard starting conditions under cold idles? and if so, how does the line run inside of the cover. I'm sure its not dumping into the throttle body. I know this sounds like a stupid question, and thats because it is. Please enlighten me. Link to comment Share on other sites More sharing options...
mikeshoup Posted May 5, 2006 Share Posted May 5, 2006 There is a fat coolant line on the water housing pipe that originally fed to the intake tract on the little 4WD cover that connect to the throttle body of my 87 rx hatch. I have removed this cover and intercooled my rx with a top mount, is this coolant line responsible for avoiding hard starting conditions under cold idles? and if so, how does the line run inside of the cover. I'm sure its not dumping into the throttle body. I know this sounds like a stupid question, and thats because it is. Please enlighten me. Sure that's a cooling line? Sounds like the AAV line. Its the valve that allows air into the intake so you can idle. If you look at the intake plenum (that 4WD cover), there's no coolant lines or anything in, just air. I beleive the purpose of the AAV being so close to the thermostat housing is so that it can feel what temperature that car's at, so it knows when it needs to idle high or low. Link to comment Share on other sites More sharing options...
Caboobaroo Posted May 5, 2006 Share Posted May 5, 2006 Sure that's a cooling line? Sounds like the AAV line. Its the valve that allows air into the intake so you can idle. If you look at the intake plenum (that 4WD cover), there's no coolant lines or anything in, just air. I beleive the purpose of the AAV being so close to the thermostat housing is so that it can feel what temperature that car's at, so it knows when it needs to idle high or low. sounds like thats what it is. If it starts better when its warm, then you need to hook your AAV back up. I'm having the same issue in my '89 RX because I also intercooled it and have yet to plumb it back into the intake. Link to comment Share on other sites More sharing options...
soobscript Posted May 5, 2006 Share Posted May 5, 2006 Not a coolant line. It's an air tube from the Auxilary Air Valve (AAV). It is responsible for idling and cold starts. The AAV is directly on top of the thermostat housing. The coolant temperature heats up a metal coil inside the AAV which directly controls how much extra air to let into the intake. Link to comment Share on other sites More sharing options...
rallyruss Posted May 5, 2006 Share Posted May 5, 2006 Not a coolant line. It's an air tube from the Auxilary Air Valve (AAV). It is responsible for idling and cold starts. The AAV is directly on top of the thermostat housing. The coolant temperature heats up a metal coil inside the AAV which directly controls how much extra air to let into the intake. thats my guess too. another intercooled RX in the area huh? we all need to meet up. I will be rallyXing mine in june up at thunder hill if you are interested. Link to comment Share on other sites More sharing options...
ryostyle_the_¥akuza Posted May 8, 2006 Author Share Posted May 8, 2006 thanks for the invite. I have a ways to go first. I've plummed the hose into a T fitting and everything starts up and idles great. Thank you for sharing the knowledge guys. Much appreciated. Link to comment Share on other sites More sharing options...
leon Posted May 9, 2006 Share Posted May 9, 2006 what i would like to know is how the aav line can still go to the throttle body if you have an intercooler. did you just drill a hole in your intercooler piping and weld a T section to it? is there any easier way? doesnt this affect the performance of the intercooler by losing pressure? what happens to the aav when running on boost? Link to comment Share on other sites More sharing options...
Loyale 2.7 Turbo Posted May 9, 2006 Share Posted May 9, 2006 thanks for the invite. I have a ways to go first. I've plummed the hose into a T fitting and everything starts up and idles great. Thank you for sharing the knowledge guys. Much appreciated. I would like to see Pics of That! Link to comment Share on other sites More sharing options...
rallyruss Posted May 10, 2006 Share Posted May 10, 2006 what i would like to know is how the aav line can still go to the throttle body if you have an intercooler. did you just drill a hole in your intercooler piping and weld a T section to it? is there any easier way?doesnt this affect the performance of the intercooler by losing pressure? what happens to the aav when running on boost? you just run a hose to the intake boot to the turbo. at least thats the easy way. I have also plumbed the line to an intercooler as well. it works but is more prone to failure in my opinion. either way will work. Link to comment Share on other sites More sharing options...
TheSubaruJunkie Posted May 10, 2006 Share Posted May 10, 2006 I drilled a hole and added a T comming out of the elbow leading to my intake. Its some sort of threaded coupler, 3/4" i believe. Once I had it threaded flush with the inside of the pipe, i had it welded in place and cut it down so it didnt stick out so far. Here it is in action: Soon im going to do the same thing, but with a 1 or 1.25" piece for my Bypass valve. -Brian Link to comment Share on other sites More sharing options...
manxsta Posted May 10, 2006 Share Posted May 10, 2006 what i would like to know is how the aav line can still go to the throttle body if you have an intercooler. did you just drill a hole in your intercooler piping and weld a T section to it? is there any easier way?doesnt this affect the performance of the intercooler by losing pressure? what happens to the aav when running on boost? once the car is warmed up the brass valve inside close,s and there is basically no flow...this unit is earthed to the thermostat housing,1 connecter is powered up as it has a heating coil inside like a auto choke, the other pin is a sensor to go to the ecu to tell how much it is open or closed 0%-100% feed input...just hook it up..its all good. Link to comment Share on other sites More sharing options...
leon Posted May 10, 2006 Share Posted May 10, 2006 once the car is warmed up the brass valve inside close,s and there is basically no flow...this unit is earthed to the thermostat housing,1 connecter is powered up as it has a heating coil inside like a auto choke, the other pin is a sensor to go to the ecu to tell how much it is open or closed 0%-100% feed input...just hook it up..its all good. Ok, so it would be easier for me to connect the aav hose to the intake air boot - the one between the afm and the turbo (if this works just as good). but how does the air flow in this hose, is it from air intake side into the thermostat? why does it have to go there? sorry if im a bit thick, but i just wanna make sure i do it properly :-\ Link to comment Share on other sites More sharing options...
gravelRX Posted May 10, 2006 Share Posted May 10, 2006 Welded up an AAV line onto mine and applied some JB weld over the weld for good measure. Looks better painted. Jay Link to comment Share on other sites More sharing options...
leon Posted May 13, 2006 Share Posted May 13, 2006 My aav is currently blocked with a bolt. i took out the bolt when the car was cold and felt a rush of vacuum before the engine died. i always thought that the aav was blowing not sucking air since it connects to the air intake duct. i thought since it is under vacuum the air must be drawn directed into the intake manifold?? so i dont understand why my engine died once i took out that bolt. it leads me to think is there any major differences by connecting the aav to the intercooler (throttle body side) or the air intake boot before the turbo. Surely i must be different if the air has to pass through the turbo first (even at idle). Link to comment Share on other sites More sharing options...
mikeshoup Posted May 13, 2006 Share Posted May 13, 2006 My aav is currently blocked with a bolt. i took out the bolt when the car was cold and felt a rush of vacuum before the engine died. i always thought that the aav was blowing not sucking air since it connects to the air intake duct. i thought since it is under vacuum the air must be drawn directed into the intake manifold?? so i dont understand why my engine died once i took out that bolt. it leads me to think is there any major differences by connecting the aav to the intercooler (throttle body side) or the air intake boot before the turbo. Surely i must be different if the air has to pass through the turbo first (even at idle). The purpose of the AAV is to allow air into the intake mani with the throttle closed. So yes, you are right in that the AAV sucks air. The reason why your engine died when you unblocked the AAV, is because it allowed air into the intake mani that didn't pass through the MAF. It cause a temporarily very lean mixture, and killed the engine. Link to comment Share on other sites More sharing options...
leon Posted May 13, 2006 Share Posted May 13, 2006 The purpose of the AAV is to allow air into the intake mani with the throttle closed. So yes, you are right in that the AAV sucks air. The reason why your engine died when you unblocked the AAV, is because it allowed air into the intake mani that didn't pass through the MAF. It cause a temporarily very lean mixture, and killed the engine. Thanks Mike. If i re route the aav to the air intake boot and disconnect the canisters auxillary air purge (turbo only) this should solve my problem right? i just wanna experiement a bit before i start drilling holes and welding pipes. :-\ Link to comment Share on other sites More sharing options...
leon Posted May 14, 2006 Share Posted May 14, 2006 had some free time today so i bought some 12.95 mm inlet diameter heater hose from my local store and connected my plugged up aav to the air intake boot as seen in the pic below http://www.ultimatesubaru.org/photos/data/500/thumbs/aav_mod_s.JPG it cost me a total of 4 dollars and took me about 10 mins trying to bend the hose into a strange shape - there is a bit of a kink in the hose that i wanna fix later on to connect the hose to the intake boot i had to disconnect the canister hose (auxillary turbo only) and plug it up im happy to say the result is great, my car starts up at 1500 rpms and goes down to about 900 after 3 mins or so. maybe im just daydreaming but my car also seems smoother and quicker throttle response. so for all you intercooled ea82's try this one if you havent already! Link to comment Share on other sites More sharing options...
SOOBOUTLAW Posted May 14, 2006 Share Posted May 14, 2006 Is your RX Hatch just like the EA81 Hatch, or a 3 door coupe? Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now