Hey everyone. I just recently bought a 1990 rx7 STU and just had a few questions. I've always wanted a FC rx7 but never had the chance to buy one and an opportunity came up and a took it. I've never worked on a rotary before but I have a decent understanding of them. When I bought the car I was told that it sat at a transmission shop for awhile and they didn't want it anymore, it turns over but doesn't crank up and I don't know where to start looking for issues. If anyone has some advice or info they could give me it would be greatly appreciated.

~Thanks,
Caleb

 

Welcome to the forum

An engine needs four things to run: air, fuel, spark, compression. Technically also timing, but the timing being messed up is unlikely.

First pull the egu fuse, crank it few times, then put back the fuse and try to start. This is how you clear a flood. You can also try adding a bit of oil through the spark plug holes to build compression.

Now, in ascending order of difficulty / cost:

Air: Pull off the airbox top and check that the filter isn't blocked. Unlikely but easy to check.

Fuel: Remove the fuel supply hose at the engine, put it into an empty bottle. Have a friend turn the key to IGN a few times and see if it pumps to prime the system. If this checks out, you can do a rough test of the injectors by tapping the leads with 12V (polarity not important) and see if you hear a click. Be careful obviously, and don't hold the leads on there for an extended period.

Spark: Use a spark checker if you want. Some people will ground out the spark plug on a bolt or other ground, then have a friend crank the engine and watch for the spark. I don't like this method for safety reasons but do it at your own risk if you want.

Compression: Use a compression tester, after removing the schrader valve in the spark plug end. You're looking for three even bounces of at least 90psi per rotor.

Lastly I mentioned timing. Remove the two small screws on top of the crank angle sensor and take off the cover. Rotate the engine until the little yellow mark on the main pulley aligns to the pointer on the front cover. Look up a picture of an aligned CAS and compare it to yours. I don't recommend removing it and realigning unless it's visibly wrong, since it's a pain to get right.

That should get you most of the way there, hopefully it works for you. Good luck