In the process of doing a silicone hose job on my FD. When I removed the stock airbox I decided to also install the Greddy Intake. In so doing it makes perfect sense to also eliminate the ACV and EGR. I bought a kit with all the blocking plates from the RX7 Store that also eliminates the AWS, ISC and Double Throttle. In reading about these last 3 though, I can't see why you would want to eliminate any of them. The ISC smooths out the idle. The AWS warms up the engine, again in order to better control the idle, and the Double Throttle protects the engine from becoming too lean during hard acceleration. Why would you want to eliminate any of these? Is there some hidden performance enhancement that I'm not seeing here?

 

The ISC is, IMHO, a good idea to keep. It does a fine job of controlling idle.

AWS is a joke. Also known as the Accelerated Wear System, it revs the engine to 3000 RPM on cold startup. JDM cars didn't have this, and it's just there to get the precat hot for US federal emissions standards. All FD's should have this removed.

Double throttle just keeps the extra throttle plates closed while the car is cold so you can't get on it while the engine is cold. Good engine safety feature, but if it's in the way or something it can be removed. It ONLY operates when the engine is cold, I have personally verified this, it operates at no other time.

Also, in theory, removing the double throttle can improve airflow.

EGR system is WORTHLESS in the FD. Mazda even ditched it in '95.

ACV is needed for routing the air pump air to where it should be to pass emissions. If you don't need it, it's fine to block off, but you really have to get in there to block it off. I'd only bother blocking it off when you're in there doing something, like fooling with the fuel injectors or rat's nest. Otherwise it's doing no harm.

Dale

 

Alright, ran into my first problem......I removed the top rear bolt that holds the TB to the UIM so I could remove the throttle cable bracket. Normally I take off the bracket then put the nut back on so I don't lose it...I guess I didn't put it back on this time and guess what...I can't find it anywhere. I had the Y-pipe out covered, so I know it didn't fall in there, but since I was just removing the UIM I hadn't gotten to the point where I had covered the LIM runners yet. I don't think the nut fell in there, but I'm really nervous about trusting my luck. Murphy's Law ya know. Any suggestions? Flame away guys...I deserve it.

 

Thanks Dale. Gonna go with your recommendation. I am going to eliminate the ACV though since I'm doing the silicone hoses and I've got it apart. No emissions in my zip code.

 

SERIOUSLY doubt it fell in the engine. I've dropped those nuts multiple times, they like to go in the motor mount wells, in the rat's nest, wherever. Did you see the nut when it got dropped?

Dale

 

Stupid question time...when removing the AWS I'm also suppose to remove the butterflies in the manifold too, right?

 

That would apply to the double throttle

 

Duh...you're right. My bad. Same question though, I do have to remove them right?

 

So, I’m knee deep in this now. I got the coils off and the solenoid rack out with no problems. I’ve tested all the solenoid valves and found that solenoid A (Pressure Regulator Control) at the very rear of the rack appears to be a little slow to release. Since I am eliminating most of the emission controls, it would appear that solenoid valves A, B, C, D and G and 2 check valves, can also be eliminated. Can anyone confirm that for me?

I also found that the wiring harness requires some attention before I re-assemble anything. The plastic sleeve on most of the harness is brittle and pretty much fell apart when I started moving things around. I have some small spiral wrap on hand, so I think I’m going to use this then wrap it with one wrap with vinyl tape. Hopefully that will withstand the heat. I found one wire that is nearly broken and I’m having a difficult time determining where it goes. It appears to be a shielded brown wire where it comes out of the harness right behind the alternator. It goes through a connector, where the wire turns black and goes down somewhere near one of the spark plugs. It looks like it might connect to a sensor that goes into the side of the housing.

 

Seriously? Nobody can confirm the removal of these relays and check vavles?

 

Dale Clark comes through again! What would this forum do without people who are knowledgeable and willing to help others out. Thanks Dale!

 

Well, nearly finished with this and I'd have to say I think it has been a success. Yesterday I found one of the metal tubes for the charge relief valve was clogged. Today I think I located the problem with my boost issues, which is what initially started this whole thing. There was a small hole in the pressure line that goes to the charge control actuator.

In addition to replacing all the vacuum lines I removed the air-pump/emissions and installed blocking plates. I repaired several wires that were on the verge of being broken and installed spiral-wrap on the harness under the UIM. I swapped out the UIM to one I had cerami-chromed, changed out the Y-pipe, swapped the intercooler input pipe to a polished one, installed power steering and alternator pulleys and changed out a coolant line that had a pin-hole leak.

Tomorrow I have to remove one of my fans cause last night I found the blade had come off the motor and was just laying on top of my radiator. From the looks of it this happened some time in the past, so no telling how long I've been running on one fan. No apparent damage to the radiator, but I might take this opportunity to install the Koyo radiator and silicone radiator hoses since I'll already have things apart.

 

Just discovered I made a minor mistake yesterday, the bad hose I found was on chamber B of the charge control actuator, which is not a pressure line. Today I did find another bad hose, the vacuum side of the turbo control actuator. Seems this hose job may have been a good call.

 

Glad you're getting things sorted out!

A small leak in the hose going to the turbo control valve will be worse on the vacuum side than the pressure side. But, any leaky hose in that system can cause weird problems.

Dale