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1987 RX Turbo EJ22 conversion


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Hey all, I have been lurking here for quite some time and even tried to sell my 1987 RX Turbo here a while back. Well now I have finally pushed this project ahead on my priorities and figured I would start to document everything here. For some back ground, I found this 1987 RX turbo abandoned at a Subaru Repair shop and had to go through paperwork hell to get a title created in my name for the vehicle. I originally wanted to keep it original with the EA82T, but the engine, along with several replacement engines (provided by the shop that had it), were all completely shot with cracked water jackets from overheating. Three years passed and I eventually decided to cave into the EJ22 swap. I have experience with engine rebuilding, but not with engine swapping so I was very hesitant. This project will take me along time to finish, and updates will be slow. I am tackling each step one weekend at a time and will probably have several questions along the way. So far, I have sent the wire harness off to SJR to be paired down, and have pulled the EJ22 and EA82T from both cars.

Edited by 1980ea71Brat
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Posted (edited)

For those wondering, I am reusing the RX clutch and pressure plate, they are at about 50% life. My primary goal is to get this conversion working 100% and then worry about clutches/rebuilt engine. Installing and removing these Subaru Engines is easy enough to do.  

I also reused the RX flywheel bolts. The EJ or RX bolts appeared to be the same length and thread pitch. No locktite, again this is mostly just for mocking up.

Edited by 1980ea71Brat
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Unfortunately there is either an issue with the clutch alignment tool or the splines on the transmission. I am going to hopefully find out which this afternoon after work. My goal by the end of this weekend is to get the engine set in and mounted to the transmission. Then I will probably look into modifying the torque beam, and a few other miscellaneous items. Maybe the radiator, or the A/C. I read in Numbchux's guide that you should ditch the A/C, but my preference is to keep it if possible, we will find out.

 

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Posted (edited)

The issue was with the clutch alignment tool. There is a 21 spline clutch and a 24 spline clutch - for some reason, Oriley's and Rock auto think the RX uses the 21 spline clutch, but its actually the 24 spline. I bough a new 'XT' alignment tool which also has a 24 spline clutch. I also finished up a bunch of other odds and ends, pictures to come later.

My current problem is getting the wiring going. I go the wire harness from SJR, but I am not sure where to tap the Black and red wire from the fuel pump relay.

I only have the switched voltage hooked up, the constant voltage, and the ground. Everything else is not plugged in. I tried tapping the black and red wire into the blue and into the gray wires leading to the fuel pump relay and neither worked to power the pump when switched power to on.

If anyone is reading this that knows something I don't, I could use a little help.

 

The solution was my switched voltage source was not correct. I have switched to the old coil voltage. This gets full voltage at turn key and drops to 9v-10v when cranking. The blue wire was the correct power wire for the fuel pump and I can hear the pump turn on when the engine turns the key.

My new problem is spark. I am getting 12.4v at the coil, and this drops to 9-10v when cranking. I think this is enough, but the engine is not wanting to start or kick off, just an occasional pop. Hopefully I will get this sorted tonight.

 

 

Edited by 1980ea71Brat
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Mate!! I’m full jelly on this RXII coupe! We never go them over here! 

And I thought by your title it would be an EJ22t conversion, but now understand where I went wrong with that. 

Anyway… 

The spark issue. I don’t like the idea of using the EA82 coil wiring for ignition power (presuming your powering the ECU via this power source?). My conversion pulled power directly from the ignition switch wiring with a fuse between the EA loom and the EJ loom. Anything that needs power between the looms should have a fuse in between and all should be sourced from under the dashboard. This also keeps the wiring neat/out of view. Where have you mounted the ECU?

The lower voltage at start on the coil seems too low to me. You want good voltage at the coil pack to produce good spark to get the engine going. 

Other things to look into: 
- are your crank and cam angle sensors plugged in their correct plugs and not swapped over? 
- is the cam belt timing correctly aligned between the two cams and the crankshaft? 
- have you tried some starter spray or fluid down the throttle body to see if the engine will fire up and momentarily run? 

Hopefully one of the above will help. 

Pitch stopper rod: fit an EJ bracket to your gearbox, cut and weld the EA82 pitch stopper rod to the resting length of the two mounts. Just cut the EA82 rod in half then fit to each mount, tack weld or brace the weld the two together good and proper. Works a treat for me. 

You’ll like the EJ22 in there, it’s a very reliable engine and is very well suited to the EA82 platform. 

Look after that AWD gearbox. It’s the only one that runs that locking centre diff and they’re very hard to find replacements for, more so over here since we never got them delivered in any of the models on offer over here. You WILL be able to spin the front wheels off the line in the right conditions under hard acceleration. Don’t do this as you’ll wear the centre diff out. It’s open or locked. No centre LSD in this gearbox. 

Enjoy! 

Cheers 

Bennie

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Posted (edited)

Bennie! Thanks for reaching out! I would LOVE to do an ej22T conversion to keep it turbo - but the old dual range AWD trans might not be able to hold that kind of power. Plus the cost of these is going for 4-5k these days! 

My constant power is directly wired to the battery with a new 30 amp fuse inline, and my turn key power is at the old coil wire with a 15 amp fuse inline - I completely agree and I think I am going to switch it to the Black/white wire at the ignition key. The main goal at the moment was to get everything working correctly before I went full bore on it.

All the crank and cam angle sensors are plugged in correctly, and none of the timing marks have changed. The engine was swapped directly out of the running 1996, WITHOUT any updates or changes to the engine. I wanted to minimize my possible errors as I worked towards getting the chasis running. - Once its running and all wired up, I am going to look into my rebuild options.

I haven't tried any starter fluid yet.... and the reason is because my fuel line burst over night! literally after I got it pop off once or twice, I called it a night and the next morning the fuel pump line was rotted and leaked over a gallon on the garage floor lol... I got some new hoses today, and I haven't felt like crawling under where the gas has spilt.

Great tip on the pitch stopper, I swapped over the ej22 pitch to the EA trans like you said, now I just have to get the old pitch stopper shortened. 

Let me tell you, finding that RX was pretty surreal. Pretty unique model here, from what my limited research has pulled up, only 2600 coupes made here in the US? Agree, I don't plan to rip any tires in it. My main goal is to get the EJ22 running for availability and maintenance, from there I have a complete interior that needs light restoration and a few rust areas to take care of.

I will probably try to make some serious progress again this next weekend when I get those fuel lines swapped out.

Thanks again!

Edited by 1980ea71Brat
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Looking good! 

There are three of these coupes in Australia that I know of. Two could be completely dead now too :( 

I was meant to mention the clutch - over here ppl used to have the EA82 pressure plate rebuilt to be stronger for the extra torque of the EJ22. Personally on my build I’ve got a highly modified version of your box to get me what I wanted for off-roading. The main part that I wanted to do was use the EJ front gearbox cases so I could keep the factory clutch and flywheel from the EJ22. 

I’ve not heard of this two spline count on the gearbox input shaft thing for 4wd boxes, only a difference between 2wd and the 4wd/AWD input shafts. The 4wd/AWD gearbox input shafts are the same as all the EJ gearbox input shafts. So that clutch disc spline difference must be the 2wd vs 4wd. 

With your permanent power you’ll be able to pull that from the ignition switch wiring too. I should have my fuse panel closer to the power sources but due to space constraints it’s located behind the glovebox (not a convenient place). The ECU is mounted on the steering column where the MPFI ECU used to live before the conversion. 

You’ll work out what works best for your conversion. I found having the front guards off makes it easier to run the wiring, same for having the dashboard out. That’s a good time to replace the heater core with an all metal unit as that plastic end ranked unit is a ticking time bomb! 

And I’m the same with AC - if you’ve got it use it! You can trigger the ECU to idle up when the AC is on, and you can have the ECU control the thermo fans via a set of relays. That also controls them for the AC from memory. 

If your alternator is a round plug unit upgrade it to the “square” plug unit. The round plug units can drop a phase and look like they’re charging but won’t be doing anything. It’s not fun. Ask me how I know.

Cheers 

Bennie

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Yeah the clutch issue was really weird because its obviously a 4x4 version but rock auto/orileys must have their parts directory wrong for the RX. Or because they are all based on the Leone, it just shows the 2wd as an option. I'd be surprised if I can find a metal heater core these days lol seems like I am 10 years too late to find parts for anything.

I might have to hit you up once I get to the A/C part. SJR labeled the wires for the A/C but I don't know exactly what I am going to need to make it run. I want to scrap the 96 Legacy ASAP but I don't want to leave anything I need on it later. Speaking of - one of the problems is also the fuel cable. apparently the cable on the loyales is long enough to not need to swap it, but on the RX there is no way to route it how the EJ was done. The EJ throttle cable is visibly longer so I will have to pull that and swap - never done a throttle cable, it doesn't look fun.

Alternator is a square unit from the 96+ era! luckily I shouldn't have an issue there. it looks like the previous owner replaced it at some point.

 

Well.... The good news is the car runs and has constant spark. I got it to idle using throttle body fluid just fine! However, after I got the fuel pump to work and replaced that disintegrated fuel line, fuel pressure was no more.

 

Now I know fuel pressure problems could be several things:

- Fuel pump

- Fuel filter

- Clogged lines

- Fuel Pressure regulators  

So naturally I started with....

 

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20220507_135823.jpg.f4f609e04c0bc8c837d407fbe02defa0.jpg

Gas tank.... 

Because I know that if someone asked me what they should do, I'd tell them to drop the tank and clean it. The car sat for 20 years and its a given that at this point its going to have garbage and junk in the tank. No sense in clogging anymore fuel lines or fuel pumps. Start at the source and work your way back to the engine.

Also, the fuel gauge doesn't work either, and I'd like to fix that. Unfortunately the fuel sending unit has been discontinued for what seems like 20 years, so I will have to find a used one from a junk yard, or try to fix this one. 

Either way, this is probably going to be my only progress this week. Today I am letting the nuts soak in penetrating fluid for 24 hours before attempting to remove them. Hopefully tomorrow I will be able to test it.

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Does anyone have any good pictures showing how the stock throttle cable is used? unfortunately their are rivets blocking access to the RX cable area and I'm not so sure I want to drill those out. (why the hell did they use rivets and not screws???)

The only reference I have found says that the stock throttle cable is just barely long enough, but it looks like it will kink and bind if I try to use the legacy cable routing.

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For the throttle cable I removed the L series cable, filed the hole in the firewall to match the fitting on the EJ throttle cable. Clipped the cabin side of the cable into the throttle pedal. Can’t remember if there were any further mods there. 

Then it was just a case of routing the throttle cable through the engine bay so it sat naturally. It sits out over the radiator from memory before it comes back into the throttle body. Mine’s RHD so it’ll be a bit different for LHD conversions I’d imagine! 

Fuel pump wiring, dunno how the EJ had it placed in the vehicle, I think I just used the power wire from the EJ loom and ran my own earth wire of the same thickness to a good earth point in the loom. It’s well over a decade since I did my conversion so these finer details are a little hazy without visiting the vehicle to see what I’ve done. 

Good to know the engine runs on starter fluid. The fuel pump could be dead. Or if the engine sat for a long time the injectors could be stuck. If this is the case, while the engine is running on starter fluid, gently give the injectors a tap with the handle of a screw driver several times. Sometimes this is enough to free them up. The next step is to have them serviced or swapped out for known running ones. 

Cheers 

Bennie

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  • 2 weeks later...

Thanks for the insight Bennie. I am going to try and work on that throttle cable next I think.

I was out of town for a week but I finally finished the fuel gauge diagnostic. The cluster itself was bad, and not sending 12v out of the right half. everything else was working properly besides that. Replaced the cluster with one out of a loyale and the gauge started working correctly.

Now to decide if my I want to reuse my sending unit or if I am should try and pull a used one. The sending unit works.... but the resistance readings are kind of intermittent and the float feels loose at the point of contact.

This project is going to take a while to finish with my availability but one small thing at a time and it will get done.

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  • 2 weeks later...

Minor updates for this project:

I got my new to me gas tank and fuel sending unit. They both came out of a 91 loyale with only 120k on the clock and they appear to be in great shape. This memorial day weekend I will be cleaning up all the surface rust at the back of the car and where the tank was, and then sealing it with POR 15. Unfortunately there are a few pin holes here and there but its mostly really solid under the car. A couple minor cancer spots that aren't obscured by the gas tank that I will get to later.

Once that is done, I am going install the new tank, replace the rest of the rubber lines, fuel filter, and get the whole fuel system working again - and hopefully get the EJ22 to run off the tank! Only concern left is weather or not I fried the fuel pump when that fuel line exploded. 

But that's the goal for this weekend. I got the parts car out of the garage today, hoping to have that taken away to wreckers sometime next week - I really hope I didn't forget to pull something off the 96 legacy!

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