Does the ACV need to be blocked off?
Thread Starter
Junior Member
Joined: Nov 2002
Posts: 12
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From: houston
Does the ACV need to be blocked off?
I want to remove my air pump, and was wondering if the ACV needs to be blocked off or could I just plug it ? Or do I have to wait on removing the pump until I get block off plates?
Full Member
Joined: Dec 2002
Posts: 111
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From: Flagstaff,AZ
Just because you remove the air pump, doesn't mean you have to remove the ACV. Although if you're going to take the time to remove the pump you might as well take off the ACV. It will no longer serve any purpose other than to get into your way and take up lots of room. I wouldn't buy the block off plate though. I made my own. I went to a metal shop and asked if they had any scrap 1/8th inch aluminum. I used the old gasket to trace the pattern then cut it myself with a hacksaw. You'll be more happy if you put a block off plate there. That way there's more room. Plus, chances are that the rubber diaphram that's inside the ACV is cracked and doesn't work anyway. BLOCK IT OFF!!!!!!!!!!!!!!
FC Mobsta
Joined: Sep 2002
Posts: 1,825
Likes: 2
From: Olympia, WA
if you wanna make it yourself thast awsome, but k2rd sells block off plate kits, or single ones..comes with all the hardware (i.e. alan wrenches, screws) www.k2rd.com
Make sure you use some rtv on the plate to make it seal.
Make sure you use some rtv on the plate to make it seal.
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I wanta be with the BUC!
Joined: Jan 2003
Posts: 2,305
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From: Knoxville, TN
It doesn't pull out it just is flat on the other side, and all you have to do is bolt it on I believe, I still have mine, and I made a block off plate for it I just am to lazy to do it. And i would have to buy a double alternator pully.
FC Mobsta
Joined: Sep 2002
Posts: 1,825
Likes: 2
From: Olympia, WA
I mean a write on how to install block off plates.
For example I am assuming that you would just
unbolt the ACV and put on the plate, but I am sure
there is more to it than that. so I was looking for a write up on that, and the rest of the plates. does
that make any sense? Lates Matt22
For example I am assuming that you would just
unbolt the ACV and put on the plate, but I am sure
there is more to it than that. so I was looking for a write up on that, and the rest of the plates. does
that make any sense? Lates Matt22
Microtech Tuning!
Joined: Feb 2002
Posts: 1,828
Likes: 0
From: 626 Socal
Originally posted by Matt22
I mean a write on how to install block off plates.
For example I am assuming that you would just
unbolt the ACV and put on the plate, but I am sure
there is more to it than that. so I was looking for a write up on that, and the rest of the plates. does
that make any sense? Lates Matt22
I mean a write on how to install block off plates.
For example I am assuming that you would just
unbolt the ACV and put on the plate, but I am sure
there is more to it than that. so I was looking for a write up on that, and the rest of the plates. does
that make any sense? Lates Matt22
2) Take it off
3) Take out the 3 screws that were screwed into LIM
4) Put sealant stuff on Block Off
5) Bolt on
.......
That good enough? It's quite simple
TII 4 SALE!
Joined: Oct 2002
Posts: 688
Likes: 1
From: Alberta, Canada
The RX-7 emissions removal mod writeup
Summary: You say that you remove your emissions controls because it "clears up your engine bay", "removes potential vacuum leaks", "is easier to debug" and "supports future modifications". But we all know that you do it because you hate the environment. You ****!
Cost: It depends on how much you want to pay. I went ultra-cheap and spent about $70.
Difficulty: This was my first mod, but I'm pretty technically proficient (just check out my phat mad Dreamwea^WHTML skills). Most people should start with something a little easier. Once you've done it, it becomes super-simple. I give it a 5/10 for difficulty.
Smiles-per-mile: 3. I've got a nice clean engine bay now! It looks nice, and is very, very, very nice to work in, but I pity whoever drives behind me. In case you didn't know, uncorked rotaries are stinky. My friends have actually complained about it.
--------------------------------------------------------------------------------
From: "Brandon Matthews"
To: FC RX-7 list
Date: Mon, April 22, 2002 11:25 am
Subject: [fc3s_org] Silicone hose job/emissions removal writeup
Okay, I'm finally going to get around to it :-) Keep in mind that "my" version was/is the "tree-hater" version. FL has no emissions testing. If yours does, don't do this without some thought :-) It's probably a pretty general job, but my car's an 89 TII, so adjust accordingly. I did the TID mod and TB mod at the same time, which eliminates a LOT of complexity. I also haven't yet bothered with a catch can for the check-and-cut valve or the PCV vent system. I will, eventually, but have omitted it here. I also installed a Fiero fan, which I highly recommend. Not only does it give me control over the fan, in conjunction with the TID, it REALLY opens up the engine bay. Corrections/additions are VERY WELCOME, since I'm going off memory here, and I spent a month or so working on it. (and a million other things...)
What you'll need to buy:
I bought an "Arospeed COLOR RACING HOSE" (*sigh*) kit from a local speed shop. It came with 10ft 4mm, 6ft 6mm, and 2ft 10mm, which was enough. I got all the hoses done, but didn't have much leftover for things like washer fluid hoses or the overflow bottle hose (oh darn). Cost: $20
You'll also need ~7ft of high-pressure 5/16" fuel hose - get the best stuff you can. You'll have some left over, but it's useful for little coolant hoses and the like. Cost: ~$25
Go to Home Depot and buy 2 "AM" bolts. Can't remember the size of the bolts, only the "code". They fit right in the 5/16" hose, and are for plugging up the TB coolant lines. Cost: $5
Get an ACV block-off plate "set" from Mazdatrix. Cost: $17
Go to a local parts store and buy a lot of hose clamps in various smaller sizes. Expect to return for many more. Where you can, keep the stock spring clamps, as they're pretty good. Also get 4ish 3/16" vacuum caps, and a pack of 100 small zip-ties. Get some "bigger" zip-ties if they've got a pack of 10ish, since you don't need many. Cost: $15+
Do you have a hose cutter? No? Go get a flat razor - they work great. Cost: $0.20
If you want to be VERY ****, buy some 39 ohm resistors to solder in place of the ACV and solenoids. That should (as yet untested) prevent the ECU from throwing codes for those bits. It won't light up the check engine light, but if you ever pull codes, you'll have to remember to not freak out when you get 6 or 7. An S5 throws the codes 29,30,31,32. Cost: $4?
Before you begin:
Some general tips:
If you can't pull a hose off, grab some pliers. With the pliers, grab the base of the hose, and twist side to side (yaw around the Z axis). It should "break" the hose free, and make removal a bit easier. Don't be afraid to use a "prying" technique to remove particularly stubborn hoses. If a hose breaks or WILL NOT come off, use your razor to cut the hose lengthwise along the length of the nipple. Carefully.
Before you get started, depressurize the fuel system by pulling the EGI fuse while the car is running. You'll still spill a good deal of fuel, but not as much.
You can NOT use silicone hose to carry oil or fuel.
I'd allocate a day or three for this job, as it's not hard, per se, just very tedious, and it's tough to make sure that you've got every single part you'll need. Refer to your Haynes/FSM vacuum diagrams often.
Zip-tie all the vac hoses with the small ties.
This mod (or series of mods) requires the removal of the cat. You can remove the airpump, too, since all it'll be doing is spinning and making funny noises.
If you remove the airpump, you'll need to re-work the water pump belt, as it'll probably slip. You've got a couple of options. RP and a few other places sell double-sheave alternator pulleys. Mitsubishi sells a stock-unit double-sheave pulley that will work, as well - check the RX-7 Forum in the 2nd-gen section. Rob Golden says that you can use a 3L220 lawnmower belt, and wrap it around the empty pulley.
You'll probably want to do the TID mod (writeup to follow soon) at the same time.
You can remove the airpump dump hose the runs toward the front of the car.
If any of your preformed hoses are cracked (as my BACV->AWSV hose was), now's a good time to replace them. If you use some silicone hose to do so, you'll have to remember to keep it from kinking (i.e. use plenty).
...and lastly...
STUDY THE ENTIRE WRITEUP FOR A GOOD LONG WHILE BEFORE YOU GET STARTED
Ready to begin?
Remove the IC. There are four hoses attached; one from the compressor outlet, one to the throttle elbow, one from the AWSV, and one to the ASV.
Unplug and label all the electrical connections to things that are attached to the UIM. IIRC, that's two connections for the ACV, the TPS, IAT sensor, AWSV, ASV, and BACV. There may be more in the way, so go ahead and disconnect those, too, if you need to.
Unplug the coolant line running to the BACV. It'll spill. Big deal :-)
Unbolt the UIM assembly. There are 4 bolts around the periphery of the UIM, and one in the middle. My dumb *** forgot about the middle one and spent a long time trying to pull off the UIM with it still in. There's a "bolt"-thing that holds the UIM to the IC mount that's a caveat. Unbolt the throttle assembly from the UIM, and wrestle the throttle cables off the TB - it's gonna take some effort the first time.
This is where an assistant is nice. Lift the UIM up and begin pulling vacuum hoses. You don't need to worry about what goes where, since you've got me and a Haynes. Unplug the 90 degree hose and curse mazda for it. If you can't get it off "right", CUT IT. Remove any leftover bits of hose.
Take a moment to admire the uglyness. Go get a beer. Begin to contemplate removal of the hard lines. Note the location of bolts and removal obstructions.
Pull the line coming from the fuel filter and going to the return line. You'll be replacing these lines.
Remove the charcoal canister and all the lines going to/from it.
Unplug the solenoids, and think about how you're going to maneuver the rack around the wiring harness. Remove the IC mount, again labelling any/all electrical connections you unplug.
Unbolt the rack from the engine. Begin to lift it up. Remove any still-attached lines. If you haven't gathered by now, most everything is coming off, so don't worry about it. Remove the rack. There's a bit of hard line that runs underneath the alternator - don't worry about that, as you can't remove it, since one section is an oil line. Remove the passenger-side hoses that ran into the stock TID. On the S-rack side, there's one line that runs to the Duty Control Solenoid (it looks "different" - you'll know it). Remove the DCS, and store it.
Unbolt the ACV and the split air pipe. The ACV has three 10mm bolts, one of which is a PAIN IN THE *** to get to. Feel around underneath and unbolt whatever you can feel. You're removing the split-air pipe, too, so go ahead and pull that. Install the ACV and split-air block-offs that you got, reusing the gaskets if you can. Some high-temp RTV works great, too.
Unplug the primary injectors. Unbolt and remove the primary fuel rail, being very careful to keep track of the spacer. You're replacing the hose that runs between the fuel rails, too.
Remove all the cooked-on rubber vacuum hose under there. Keep track of the MOP spider splitter - you're reusing it.
First, we're replacing vacuum hoses. Now may be a good time to do a quick test-fit of the UIM, so that you know about how long the silicone hoses should be. You're running line from the following locations to the BACK of the UIM, except the first:
between the secondary injectors
from the back of the secondary injector ports
from between the primary injectors
from each oil injector -> 4-way splitter
from the fuel pressure regulator (on the secondary rail)
from the brake booster hard line
The FPR line MUST go to the BOTTOM nipple on the back of the UIM.
After you've got the vacuum lines laid out, reattach the primary fuel rail, running new hose between the rails. Now run line from the fuel filter -> primary fuel rail, and from the secondary fuel rail -> fuel return line. I double-clamped my fuel hoses, and recommend that you do the same.
Perform the TB mod.
There are two TB coolant hose issues that need to be dealt with. One line comes from the water filler neck, and the other goes into the rear endplate. Cut about 4" of hose (either fuel or coolant) and clamp it on the respective nipple. Insert a bolt, and clamp the bolt. MAKE SURE that your engine-side block-off is long enough to be bent out of the way of the UIM. If it's not, the bolt will stick straight up, and prevent the UIM from seating properly. Your fuel lines must also lay flat on the engine, or they'll be in the way.
Now's a good time to replace the lines going to the Pressure Sensor and BOV. You can use the stock tee. There's a stock nipple underneath the BACV that you can use, having eliminated the ACV. Speaking of nipples, cap the three on the front of the UIM.
Now you need to think about where you're going to mount the DCS (Duty Control Solenoid). I mounted mine next to the alternator, on the throttle cable mount tab. Use some 6mm hose and connect it to the correct sub- alternator hard line (the one that comes from the wastegate line). I imagine that there could be gains to be had from mounting it closer to the wastegate, but I didn't bother.
So you've got the fuel lines redone, and the coolant hoses blocked off. Replace the UIM, remembering to bend that little coolant hose out of the way, making sure to not pinch any hoses or wires, and keeping track of all your vacuum hoses. Attach the FPR to the bottom nipple, and the other three as you can. The 6mm hose coming from the vac spider goes on the bigger of the remaining three (duh).
Attach the line coming from the brake booster to the horizontal nipple near the throttle cable attachment point.
Wind the AWSV and BACV wiring around whatever's necessary and reattach them. NOTE: This can get difficult, as your fuel lines and vac lines can be pretty in-the-way. If needed, pull the UIM again and reseat things to make room. You'll get pretty good at pulling the UIM eventually - I know I am.
You should have been reconnecting things as you went along. Don't worry too much if you've got "extra" connectors. There are many around the engine bay, and you've just removed 5ish electrical connections. Go ahead and start reconnecting things.
Reinstall the IC and anything else you need to before you start the car. Prime the fuel system and check HARD for leaks.
Don't be surprised if the car won't idle right away - the TB mod does that. You'll probably also need to adjust the throttle cable slightly. You may also flood the engine (I did). Now's a good time to change your spark plugs/wires.
That about does it. Good luck!
Summary: You say that you remove your emissions controls because it "clears up your engine bay", "removes potential vacuum leaks", "is easier to debug" and "supports future modifications". But we all know that you do it because you hate the environment. You ****!
Cost: It depends on how much you want to pay. I went ultra-cheap and spent about $70.
Difficulty: This was my first mod, but I'm pretty technically proficient (just check out my phat mad Dreamwea^WHTML skills). Most people should start with something a little easier. Once you've done it, it becomes super-simple. I give it a 5/10 for difficulty.
Smiles-per-mile: 3. I've got a nice clean engine bay now! It looks nice, and is very, very, very nice to work in, but I pity whoever drives behind me. In case you didn't know, uncorked rotaries are stinky. My friends have actually complained about it.
--------------------------------------------------------------------------------
From: "Brandon Matthews"
To: FC RX-7 list
Date: Mon, April 22, 2002 11:25 am
Subject: [fc3s_org] Silicone hose job/emissions removal writeup
Okay, I'm finally going to get around to it :-) Keep in mind that "my" version was/is the "tree-hater" version. FL has no emissions testing. If yours does, don't do this without some thought :-) It's probably a pretty general job, but my car's an 89 TII, so adjust accordingly. I did the TID mod and TB mod at the same time, which eliminates a LOT of complexity. I also haven't yet bothered with a catch can for the check-and-cut valve or the PCV vent system. I will, eventually, but have omitted it here. I also installed a Fiero fan, which I highly recommend. Not only does it give me control over the fan, in conjunction with the TID, it REALLY opens up the engine bay. Corrections/additions are VERY WELCOME, since I'm going off memory here, and I spent a month or so working on it. (and a million other things...)
What you'll need to buy:
I bought an "Arospeed COLOR RACING HOSE" (*sigh*) kit from a local speed shop. It came with 10ft 4mm, 6ft 6mm, and 2ft 10mm, which was enough. I got all the hoses done, but didn't have much leftover for things like washer fluid hoses or the overflow bottle hose (oh darn). Cost: $20
You'll also need ~7ft of high-pressure 5/16" fuel hose - get the best stuff you can. You'll have some left over, but it's useful for little coolant hoses and the like. Cost: ~$25
Go to Home Depot and buy 2 "AM" bolts. Can't remember the size of the bolts, only the "code". They fit right in the 5/16" hose, and are for plugging up the TB coolant lines. Cost: $5
Get an ACV block-off plate "set" from Mazdatrix. Cost: $17
Go to a local parts store and buy a lot of hose clamps in various smaller sizes. Expect to return for many more. Where you can, keep the stock spring clamps, as they're pretty good. Also get 4ish 3/16" vacuum caps, and a pack of 100 small zip-ties. Get some "bigger" zip-ties if they've got a pack of 10ish, since you don't need many. Cost: $15+
Do you have a hose cutter? No? Go get a flat razor - they work great. Cost: $0.20
If you want to be VERY ****, buy some 39 ohm resistors to solder in place of the ACV and solenoids. That should (as yet untested) prevent the ECU from throwing codes for those bits. It won't light up the check engine light, but if you ever pull codes, you'll have to remember to not freak out when you get 6 or 7. An S5 throws the codes 29,30,31,32. Cost: $4?
Before you begin:
Some general tips:
If you can't pull a hose off, grab some pliers. With the pliers, grab the base of the hose, and twist side to side (yaw around the Z axis). It should "break" the hose free, and make removal a bit easier. Don't be afraid to use a "prying" technique to remove particularly stubborn hoses. If a hose breaks or WILL NOT come off, use your razor to cut the hose lengthwise along the length of the nipple. Carefully.
Before you get started, depressurize the fuel system by pulling the EGI fuse while the car is running. You'll still spill a good deal of fuel, but not as much.
You can NOT use silicone hose to carry oil or fuel.
I'd allocate a day or three for this job, as it's not hard, per se, just very tedious, and it's tough to make sure that you've got every single part you'll need. Refer to your Haynes/FSM vacuum diagrams often.
Zip-tie all the vac hoses with the small ties.
This mod (or series of mods) requires the removal of the cat. You can remove the airpump, too, since all it'll be doing is spinning and making funny noises.
If you remove the airpump, you'll need to re-work the water pump belt, as it'll probably slip. You've got a couple of options. RP and a few other places sell double-sheave alternator pulleys. Mitsubishi sells a stock-unit double-sheave pulley that will work, as well - check the RX-7 Forum in the 2nd-gen section. Rob Golden says that you can use a 3L220 lawnmower belt, and wrap it around the empty pulley.
You'll probably want to do the TID mod (writeup to follow soon) at the same time.
You can remove the airpump dump hose the runs toward the front of the car.
If any of your preformed hoses are cracked (as my BACV->AWSV hose was), now's a good time to replace them. If you use some silicone hose to do so, you'll have to remember to keep it from kinking (i.e. use plenty).
...and lastly...
STUDY THE ENTIRE WRITEUP FOR A GOOD LONG WHILE BEFORE YOU GET STARTED
Ready to begin?
Remove the IC. There are four hoses attached; one from the compressor outlet, one to the throttle elbow, one from the AWSV, and one to the ASV.
Unplug and label all the electrical connections to things that are attached to the UIM. IIRC, that's two connections for the ACV, the TPS, IAT sensor, AWSV, ASV, and BACV. There may be more in the way, so go ahead and disconnect those, too, if you need to.
Unplug the coolant line running to the BACV. It'll spill. Big deal :-)
Unbolt the UIM assembly. There are 4 bolts around the periphery of the UIM, and one in the middle. My dumb *** forgot about the middle one and spent a long time trying to pull off the UIM with it still in. There's a "bolt"-thing that holds the UIM to the IC mount that's a caveat. Unbolt the throttle assembly from the UIM, and wrestle the throttle cables off the TB - it's gonna take some effort the first time.
This is where an assistant is nice. Lift the UIM up and begin pulling vacuum hoses. You don't need to worry about what goes where, since you've got me and a Haynes. Unplug the 90 degree hose and curse mazda for it. If you can't get it off "right", CUT IT. Remove any leftover bits of hose.
Take a moment to admire the uglyness. Go get a beer. Begin to contemplate removal of the hard lines. Note the location of bolts and removal obstructions.
Pull the line coming from the fuel filter and going to the return line. You'll be replacing these lines.
Remove the charcoal canister and all the lines going to/from it.
Unplug the solenoids, and think about how you're going to maneuver the rack around the wiring harness. Remove the IC mount, again labelling any/all electrical connections you unplug.
Unbolt the rack from the engine. Begin to lift it up. Remove any still-attached lines. If you haven't gathered by now, most everything is coming off, so don't worry about it. Remove the rack. There's a bit of hard line that runs underneath the alternator - don't worry about that, as you can't remove it, since one section is an oil line. Remove the passenger-side hoses that ran into the stock TID. On the S-rack side, there's one line that runs to the Duty Control Solenoid (it looks "different" - you'll know it). Remove the DCS, and store it.
Unbolt the ACV and the split air pipe. The ACV has three 10mm bolts, one of which is a PAIN IN THE *** to get to. Feel around underneath and unbolt whatever you can feel. You're removing the split-air pipe, too, so go ahead and pull that. Install the ACV and split-air block-offs that you got, reusing the gaskets if you can. Some high-temp RTV works great, too.
Unplug the primary injectors. Unbolt and remove the primary fuel rail, being very careful to keep track of the spacer. You're replacing the hose that runs between the fuel rails, too.
Remove all the cooked-on rubber vacuum hose under there. Keep track of the MOP spider splitter - you're reusing it.
First, we're replacing vacuum hoses. Now may be a good time to do a quick test-fit of the UIM, so that you know about how long the silicone hoses should be. You're running line from the following locations to the BACK of the UIM, except the first:
between the secondary injectors
from the back of the secondary injector ports
from between the primary injectors
from each oil injector -> 4-way splitter
from the fuel pressure regulator (on the secondary rail)
from the brake booster hard line
The FPR line MUST go to the BOTTOM nipple on the back of the UIM.
After you've got the vacuum lines laid out, reattach the primary fuel rail, running new hose between the rails. Now run line from the fuel filter -> primary fuel rail, and from the secondary fuel rail -> fuel return line. I double-clamped my fuel hoses, and recommend that you do the same.
Perform the TB mod.
There are two TB coolant hose issues that need to be dealt with. One line comes from the water filler neck, and the other goes into the rear endplate. Cut about 4" of hose (either fuel or coolant) and clamp it on the respective nipple. Insert a bolt, and clamp the bolt. MAKE SURE that your engine-side block-off is long enough to be bent out of the way of the UIM. If it's not, the bolt will stick straight up, and prevent the UIM from seating properly. Your fuel lines must also lay flat on the engine, or they'll be in the way.
Now's a good time to replace the lines going to the Pressure Sensor and BOV. You can use the stock tee. There's a stock nipple underneath the BACV that you can use, having eliminated the ACV. Speaking of nipples, cap the three on the front of the UIM.
Now you need to think about where you're going to mount the DCS (Duty Control Solenoid). I mounted mine next to the alternator, on the throttle cable mount tab. Use some 6mm hose and connect it to the correct sub- alternator hard line (the one that comes from the wastegate line). I imagine that there could be gains to be had from mounting it closer to the wastegate, but I didn't bother.
So you've got the fuel lines redone, and the coolant hoses blocked off. Replace the UIM, remembering to bend that little coolant hose out of the way, making sure to not pinch any hoses or wires, and keeping track of all your vacuum hoses. Attach the FPR to the bottom nipple, and the other three as you can. The 6mm hose coming from the vac spider goes on the bigger of the remaining three (duh).
Attach the line coming from the brake booster to the horizontal nipple near the throttle cable attachment point.
Wind the AWSV and BACV wiring around whatever's necessary and reattach them. NOTE: This can get difficult, as your fuel lines and vac lines can be pretty in-the-way. If needed, pull the UIM again and reseat things to make room. You'll get pretty good at pulling the UIM eventually - I know I am.
You should have been reconnecting things as you went along. Don't worry too much if you've got "extra" connectors. There are many around the engine bay, and you've just removed 5ish electrical connections. Go ahead and start reconnecting things.
Reinstall the IC and anything else you need to before you start the car. Prime the fuel system and check HARD for leaks.
Don't be surprised if the car won't idle right away - the TB mod does that. You'll probably also need to adjust the throttle cable slightly. You may also flood the engine (I did). Now's a good time to change your spark plugs/wires.
That about does it. Good luck!