Radiator fan and Power FC issue along with others
 

First off I am new to rotaries but not to forums :) I've been searching for awhile and can't seem to find a definitive answer. Some of the threads just stop. Maybe I am not using the right keywords or my computer sucks?

Anyways, I bought the car its a 93 with the 1.3L twins and they are still sequential.

Here's the mods list engine wise from what I was given:
-greddy intercooler
-hks turbo inlets
-greddy exhaust
-exedy twin disk
-cusco 1.5 way diff
-walbro 255
-apexi power fc tuned to 375 whp by steve kan
-mishimoto radiator
-brand new oem water pump
-aspx wideband
-glowshift digital boost gauge



Many of the treads I've found say to just keep the stock radiator and fans which I would be fine with if I had them. The car came with an aftermarket radiator and fan set up. Currently, well before I took it apart, the fans are hardwired to the battery so every time I stop I need to disconnect the battery.

In this thread: https://www.rx7club.com/3rd-generati...wiring-781234/ they talk about wiring the positive and negative of the fans into the factory harness. The fans are 2 wire each and the factory plugs are 4 wire. From the looks of it the white wire would go to the positive of the fan. Would the ground then go to the blue/orange wire running to the relay like the last post suggests? Is it even worth trying to make that work or should I just get a temperature sensor to trigger a relay to simplify it?

The car also came with an Apexi tuner and was told it has an aftermarket ECU so I'm assuming it is the Power FC. When I go into the Power FC FAQs and whatnot all the links are dead, for me at least. Does anyone have any of the FAQs and whatnot saved off that you could post please?

Again being new to rotaries I am not sure what I can all get away with when it comes to removing things. I've read a bunch of threads on deleting the emissions and simplifying the rats nest with a custom solenoid rack but none of them say anything about tuning afterwords. Am I able to just pull all that stuff off, block what needs to be, and just go? There are a few aftermarket pieces on the engine but from the diagrams and whatnot that I have found it looks like all the emissions stuff is still there. I don't need to do emissions so I want to simplify it up as much as I can.

I just replaced most of the capacitors on the cluster and the odometer still doesn't work. All of the other capacitors that I didn't replace all looked good and had not marks on or below them. I haven't started the car yet to see if the tach and speedo work at least.

I'm stupid when it comes to wiring and avoid it whenever possible. BUT...there is the wiring diagrams at the back of the Factory Service Manual that might help. And a copy of the manual is available for download in the 3rd Gen. FAQ.
Not sure who would recommend keeping a used stock radiator. While they were efficient and adequate for the car, they have plastic end-tanks which typically fail. Almost anyone who's owned an FD for any time at all changes them for an all aluminum version. KOYO or FLUIDYNE are popular. And they make then specific for the FD...with mounts for the factory fan assembly, lower nipple for the AST and a drain-cock.
I DO agree that if you can find a used fan assembly and get it operable there is not much out there better. Hopefully the PO didn't hack up the wiring too badly, but since you didn't mention them, I'll assume the relays were tossed too.
As for what you can get away with...EVERYTHING on a rotary IMHO begins with cooling. Doubly true when it's forced induction.

I'll also toss this out. Might help just in case you missed it earlier....

https://www.rx7club.com/3rd-generati...ntrols-876767/

Thanks for the reply. It seemed like a majority of the radiator debates had people saying to keep the stock radiator. Either way I have an aftermarket one now so I have to go with that. The relays and whatnot all look like they are still there. It looks like he just unplugged the old fans and radiator and replaced them with the aftermarket ones which were then hardwired to the battery. Would it be easier to try and utilize the relay system in the car, if it is all still there, or just use a temperature switch to trigger a relay, or two, to turn the fans on?

Thanks for that link I must have missed that. I probably skimmed past it or it didn't come up since it was "engine" based. I'll give that look over.

Still curious on the emissions stuff. I want to pull it all off but I don't know if I have to do anything tuning wise after the fact.

I also updated the first post with the modifications that are done to the car.

I would utilize the stock fan control system if the relays and wiring are in place. A thermoswitch located on the back of the waterpump housing initiates (IIRC) low fan speed which will increase with additional load inputs...probably explained better in that link I gave you. It's probably more appropriate for later when you get it operating properly, but the stock thermoswitch threshold is 108 C. Many, myself included, replace it with the S5 thermoswitch from an 89-91 RX7 for a threshold of 95 C. It's a P n P. I think there are also ways to play with the threshold with the PFC too.
Check the Parts For Sale section for a stock fan assembly and make sure that radiator you have is specific for the FD and will accept the shroud etc.

As for emissions delete, if you can decipher my sig, you'll know I've deleted emissions. You have the PFC already, just need a block-off set and a keen study of the appropriate solenoids. You shouldn't need a re-tune as there won't be any dramatic power bump...just ALOT simpler, a little lighter and more space. I strongly recommend an idler pulley to take the place of the air-pump. Many try to get by on an under-drive pulley set, but even with the larger pulleys IMO there isn't sufficient belt contact with the waterpump. Search and consider double-throttle removal as well.

Ok I'll see if I can find out if this radiator will fit the stock fans. I've been reading about the emissions delete and whatnot I just couldn't find anything pertaining to needing a re-tune. I've also read a bit about the dual throttle delete and some other stuff. The car will not get driven in the winter/cold at all so much of the warm up systems and whatnot are not needed.

Thanks for the help. I see you are in the midwest. Where are you?

No problem, you're welcome.

Omaha area...
While you're new, feel free to post up here for help. We all started somewhere. But there's a Midwest section on the forum, including a Midwest "for sale" section that you might try when you can. A lot of guys in the Chicago/Minneapolis-SP area, including Wisconsin that you may try to network with for the assembly and fellow-owner support. Seems like there was a meet thread not long ago. Not sure if it's passed.

Ah sounds good. Yea I checked out the midwest section a little bit. Been mainly reading on a lot of things instead.

I got the radiator fan issues figured out. Turns out they were all wired and ready to go using a temperature switch and relay set-up but seems like he couldn't figure out why they wouldn't turn on at the specified temp and just hardwired them. When I did some more digging in the wiring to clean up the rats nest that was in there I found that he used 5 prong relays instead of 4 prong ones causing the relay to not work right since the center prong was left disconnected. Swapped in some 4 prong ones and works like a charm.

There was also a shit load of wiring left over from old gauges so I pulled all of that out and re-ran a new cleaner wiring set up. Have boost and a wideband for now. Just need to get the sensor into a bung and it will be all good to go. Took her for a spin around the block and the speedo, tach and odometer still don't work. Going to pull them back apart and check the solder joints and everything out at work.

Also fixed my driver side passenger window switch since it wasn't working and installed aerocatch hood latches since the car doesn't have a hood latch. Just need to get the hood struts in and I wont have to use the panhard bar from my firechicken as a hood prop anymore :lol:

When I was going through an cleaning up wiring I noticed that there were some plugs in the passenger footwell that are unplugged and one of the wires from the ecu isn't grounded to anything. I didn't want to ground it or look for the other plug since the car is running fine. Are there any plugs and whatnot on that side that are used as test connections or something so they aren't plugged in all the time?

Sounds like good progress on bringing it back from the brink. :bigthumb:

Is one a black with yellow striped wire? ---> Cooling Fan Test Proecdure and FAQ

Yea she's coming along nicely so far. I took a few pictures of the wires I am talking about.

(looks like black with white stripes to me and it just has a ring connector on the end)
http://i855.photobucket.com/albums/a...psmrp39zwr.jpg

Then there's this one
http://i855.photobucket.com/albums/a...psnlysbrt7.jpg

lastly is this one
http://i855.photobucket.com/albums/a...psm57yl2ta.jpg

Moved the pics on accident. Here they are again in the same order
Attachment 621296

Attachment 621297

Attachment 621298

^Post is almost a year old so I re-read it. Regarding radiators, what exactly is the question? I thought it was fairly self-explanatory. The stock radiator was adequate for a stock car. IMO it was efficient and effective in that capacity. It's weakness was two-fold really. The end-tanks were plastic. With age and heat that plastic fatigued over time. Plastic became brittle and the tanks had some history of failing. Sometimes catastrophically with the potential of cooking the engine...especially if the owner was still relying on a useless stock temp gauge. It's other weakness was capacity if the engine had performance modifications like higher boost which added more heat. Most owners replace the stock radiator (and AST) with all-metal versions that have increased capacity.

FAQs
 

This s all great stuff

my fans wont work with A/C off
 

any help why my fans wont work with A:C off? Car will overheat because fans won kick in unless I have the A/C on

is this thread from 2015?
anyways try replacing your temp sensors. obviously fans work but since they are only kicking on with the AC it sounds like the ecu dosen't know what the temp is.