Bought my ‘93 FD in 2006 with 102k on the odometer. Engine rebuilt/new turbos @92k by Rob Golden of Pineapple Racing (GBNF). The FD was my 3rd RX7, first 2 were FB’s. Anyway, moved back to IL unexpectedly in 2012 after getting disabled by a work related accident to care for my dad who had Alzheimer’s. Before/during this transition I had some custom intercooler work done, but didn’t get to test it before I left Seattle. The first time I drove the car in IL I found it wasn’t boosting properly. Primary boost was only getting to <8lbs, so 2nd turbo never came online at all. I didn’t have a place to work on it, so I parked it. There are NO rotary shops in this area and no mechanics that seem to know anything about a rotary. I kept the battery charged and started the car religiously every week up until about 4 years ago when for some reason it wouldn’t start. After repeated attempts I put Marvel Mystery Oil in the combustion chambers and kind of lost interest (bought a motorcycle). I did intermittently spin the engine by hand so it is not locked up and rotates very smoothly. Now I’m interested in getting it back going again. I have a very nice shop now to work on it now, but every place I seek advice from says I should rebuild the engine even though it only has about 30k miles on it. They say it’s from sitting for an extended period of time, but I’ve read numerous articles about rotaries that sat for 10 years or more that were able to be restarted and ran fine with only minimal service. I would say I was moderately familiar with rotaries when I moved back here, but after 12 years I’m sure I have forgotten plenty. My first inclination is to just try to get the car started without rebuilding and see where I stand. The flip side is I plan to have the engine street ported and perhaps go single turbo at some point. I guess I’m just looking for opinions on which way to go from people who are more knowledgeable on this than I am.

 

If the motor is clean and in good condition, the individual pieces will have considerable value for a rebuild.

Plunk in an new motor and take your time rebuilding the old motor.

MInd you, in the process of plunking in a motor you will likely find much of the engine bay has aged out.

Budget an additional $5000 to replace all periphferal parts.

 

"Can" it run "fine" again after having sat for several years?

Yeah. Sure. It has happened. But it's not super likely.

In this case, it's not just the 4 years without running at all, but several years even beyond that where it sounds like it was only started and allowed to idle. That's not great for a rotary that needs to run through the full rev range to mitigate carbon build-up.
There's a better-than-not chance that you've got stuck apex seals -- which is what you would have been trying to solve with the Marvel Mystery Oil. And if they were possibly stuck 4 years ago, they certainly are by now.

Sounds like you want to do a port job anyways and convert to single turbo. No better time than when you yank the engine the rebuild it.

In the grand scheme of everything you're likely going to need to do on that kind of build, plus everything else the car will need after sitting ~15 years, the cost of rebuilding the engine (especially if you do it yourself) will be a rounding error.

If the engine will at least turn over, you can get a compression tester and see where it stands. I think a rebuild is in your future regardless -- even if you get this one "running" (to any degree, even well). But if it'll make you feel better just to know that skipping straight to rebuilding isn't a "waste", it's a good tool to have anyways.

 

No stuck Apex seals. As stated in the original post engine spins smoothy by hand. Mystery oil was introduced to help prevent engine seizure as recommended in steps for long term storage of a rotary.

The rest of your comments are noted and appreciated.

 

If the seals are stuck down (so stuck into the rotor, not stuck against the housing), as can happen from sitting, the engine will turn over just fine. It just won't have any compression and not start. But, if it happened while you were starting the car every week or so, this isn't super likely. Unless maybe the fuel was super-old and varnish-y, which can make sticking happen rapidly. But, really, 'no starts' can be SO MANY things it's impossible ascertain what was going on 4 years ago.

 

I don’t think this is my problem. I’ve got the plugs out right now and you can feel the “compression “ come out when you spin the engine.

 

If you've confirmed the engine has compression, I would make sure it's getting fuel. Are the spark plugs dry or wet and smelling like gasoline when you remove them? If it's got fuel, I would try fresh spark plugs and ignition wires next.

 

i would definitely try to get it running as is and go from there.

I'd start by checking the fuel system. Remove the pump and look for rust in the tank. Hookup a gauge to test the fuel pressure. Go from there.

Nice to see your user name again.

Good luck!

 

vol96 has a great running DROP-IN engine
7K miles , compression in the 120's
2 day install and your ON-THE-ROAD-AGAIN

 

"i would definitely try to get it running as is and go from there.

I'd start by checking the fuel system. Remove the pump and look for rust in the tank. Hookup a gauge to test the fuel pressure. Go from there.

Nice to see your user name again. "

what he said for sure.

 

The motor may only have 30,000 miles on it, but it has been around the sun 20 times since it was rebuilt.

How much of the supporting infrastructure was renewed in 2006, or is a lot of the engine bay 33 years old now?

In any event you may find yourself chasing innumerable gremlins in a downward spiral to the eventual complete restoration and rebuild.

In the meantime, how long will Mazda keep feeding new motors and components into the enthusiast market?

 

Chill out, man. Quit slinging negative presumptions and platform doom, and let people enjoy and experience their cars.

@dblboinger Just pull the plugs, funnel and tube in some MMO, let it soak for a day, pull the fuel pump fuse, and then turn the engine over with the starter. After you've had a good number of rotations to move the MMO out, pull the plugs and crank it a little more with the plugs out ( you may want to put some shop rags over the holes to prevent the oil mist form making a huge mess). Follow up with a new set of platinum plugs (NGK BUR7EQP and BUR9EQP) and remove the charge pipe before the throttle body.

Put the fuel pump fuse back in and put a jump pack on the car. After that, hold the throttle open by hand and give the car a nice shot of starting fluid. Hop in the driver's seat and crank it, feather the throttle as needed. If it tries to start and doesn't do anything, grab a helper to spray shots of starting fluid into the intake as you hold the pedal to the floor and crank.

If it will only run on the starting fluid you'll need to check your fuel system. Start with fuel pressure and work back from there.
If the car won't start at all, pull the plugs, clean them, and check for spark.
Don't throw in the towel and fire off the parts cannon until you've figured out if it's a go/no go situation. Once it's running, refresh other things.

I recently got a car running that was probably sitting for 12-15 years, after refreshing some top end components (including injector cleaning). I dumped 5 gallons of fresh 93 in with a liberal amount of premix and it fired off on my first crank attempt. After some minor idle adjustments, the car ran great.

 

OK. Sorry. Yolo, and all that.