mazdaverx713b

iTrader: (91)

the car is coming along well and making progress every week. i have put just over 100 miles on it since the swap. runs excellent. minor issues here and there. tomorrow will be new front wheel bearings. here is the link to the new thread i started. i felt that this one was too big and people are sick of seeing it and dont care about the progress of the car due to the large amount of reading. here's the new thread with current pics: https://www.rx7club.com/build-threads-293/85-l6-gs-se-project-restoration-822222/

mazdaverx713b

iTrader: (91)

I just reread this thread and I have been so happy with this car. Its been a long journey and I appreciate the car so much! The hard work definitely paid off!

BrycenP

Hey Dave, just read through the whole thread and have to say i'm thoroughly impressed, and frankly very happy to see that you still have the car and are still active on the forum. FYI this is my first response on the forum so yay me. I'm new to RX7s and in the process of preparing for a similar swap and I was hoping you could give me some insight on the process. Before that though ill give you a little background. I bought a rust bucket 85 gsl-se in february that was rebuilt about 25k miles ago and runs great considering its been lightly modified(header, k/n intake, uprated clutch and LSD from what i can tell). I initially I planned on fixing the rust, painting it and driving it until rusted out again. However, upon digging into it more I realized it would be more work than it was worth. I live in hawaii and there are very few 7s left here in any decent shape. I eventually found a running, rust free 85 gs in california that fit the bill for a swap so I bought it and shipped it out. Id be happy to share some photos if you're interested!


I'm mainly curious about the wiring issues you faced, and if looking back there were any glaring issues that wouldn't have been solved by a donor car? Sourcing parts here is a bit of a nightmare and i'm trying to compile and order everything I can ahead of time.


Thank you for any insight you might like adding.

mazdaverx713b

iTrader: (91)

I'm glad you found this thread! I started another shortly after the car was running and still continue the thread to this day!

As for the swap, everything from the GSL-SE will bolt into the rust free GS. The dash will have to be pulled and the carpet lifted on the left side as you will need to replace the entire wiring harness. The GSL-SE's harness is a direct fit into the GS and will connect to the GS's harness under the driver's side storage bin. So you will not have to worry about the rear harnsess. You will need to transfer over the fuel lines as they are different, as is the tank and pump and filter assembly. I'd be happy to cover anything you need if you need more advice!

BrycenP

Hey, I really appreciate the insight! Wanted to give you a little update. Got the motor and harness out of the donor car last weekend. Got the 12A ready to be pulled out over the last two nights. Going to pull it this afternoon and try to get the 13B in. Still need to pull the tank, pump and lines but crossing my fingers they come easy. Wish me luck!

mazdaverx713b

iTrader: (91)

That sounds like you're making good progress. Message me if you run into any snags or need advice or pictures. I can always shoot you my number so you can text me for a faster response.

BrycenP

Hey Dave,

Been slow and steady on my GS/SE so far but making progress. Have the engine in, fuel tank/pump swapped as well as the sender line from my SE. Got the SE harness through the firewall today and hoping i can get her running by next weekend. Been using your build thread as bible and planning on digging into it even more as i get into the nitty gritty of the wiring.

Thanks!
Brycen

mazdaverx713b

iTrader: (91)

Glad to hear that you're making progress and that my thread is helpful. Are you using the compete GSL-SE harness? If not, you will have to pull the dash and swap it as it has wiring for the coolant temp and oil pressure sender as well as the main relays.

BrycenP

Yeah, I've got a complete harness from a my donor car. Dash is currently out, and I'm not sure how I would have been able to do it otherwise. Do you mean the sub-harness that sits behind the dash has the wiring for the coolant sensor and oil pressure sender unit?

Thanks

mazdaverx713b

iTrader: (91)

The sub harness does not, but the main harness does. That's the issue that I ran into. Figured I could just swap the small sub harness that hooks to the ecu but I realized that the main12A harness was missing a bunch of SE specific stuff. I swapped the entire harness over. The only harness thats original is the rear harness. It mates with the SE harness under the driver's side storage bin. I didn't swap it because its the same harness for all trim levels.

BrycenP

Gotcha, thanks for the heads up! I have both routed through the firewall and have started hooking them but have a question about the Switch sub harness behind the dash. Did you retain your GS one, or modify the SE one? My GS has the cable operated fan controller as opposed to the servo operated one in the SE. My SE switch-harness also has the a spiderweb of aftermarket audio wiring that id like to avoid reusing if i can. Appreciate all the help, hoping to get it running this weekend!

mazdaverx713b

iTrader: (91)

I kept the original heater controls. For some reason I'm thinking that the heater controls were a separate sub harness. I honestly don't remember unfortunately.

BrycenP

Hey, got my car running this last weekend!! Beyond stoked! Still have a bunch of details to take care in the interior and its idling really high so I'm guessing I have a vacuum leak somewhere. Wanted to say thanks for all the quick responses and insight, really appreciate it! I'll send some photos once i get it all back together!

mazdaverx713b

iTrader: (91)

Glad to hear you got it up and running!! Was the heater harness a sub harness as I had thought? Feel free to send any pictures you have of the car!

BrycenP

Hey, Wanted to reach out and update you with my project and say thanks again for the support on getting my swap going and giving me the courage to dive into it. The car is now (mostly) mechanically done in that i finished the full SE swap(engine, fuel, suspension, axles) and replaced most of the steering components, suspension bushings, and consumables. The car runs decently but as time has gone on it has developed a slight misfire at idle. First i replaced all of the ignition components as well as ignitors. Then I replaced all of the vacuum lines and out of an abundance of caution i replaced the gasket between the upper and lower intake manifold. Upon getting it all back together it ran slightly better but it was probably just a placebo. After hearing it still miss after it warmed up I started fiddling with the vacuum lines that go under manifold and heard its idle change. Long story short I realized that my issue was actually with the wiring loom feeding the injectors....

This sucks but i shouldn't be surprised considering my donor car had ~230k. I replaced the connector clips to the injectors during the swap because mine were brittle and one broke but kept the original wires. I'm planning on pulling the loom apart and trying to identify/repair the problem myself but i may be in the market for a new SE motor harness(passenger side).

I'm getting there and will try to get some photos up soon! Thanks again and stoked to see you reviving your L6 project!!!

BrycenP

And Yes, the heater harness was a sub harness that was the same between both cars!

mazdaverx713b

iTrader: (91)

That's great news!! Super glad you got it up and running! Also glad to hear that the heater harness was a separate sub harness. I couldn't remember. You should definitely start a build thread documenting your progress. Would love to see pictures of the car!

mazdaverx713b

iTrader: (91)

I've been getting mine ready to drive again. Its sat for a few years unused so it needed some work.

eprx799

iTrader: (8)

I’m glad you still have this FB. It’s nice to see my old engine is still alive.

mazdaverx713b

iTrader: (91)

Marc, it runs unbelievably well! Compression is top notch and its very smooth. I've had many offers over the years to sell the car and or the engine and I will refuse every time. I plan to hang onto this one for a long long time.