So after doing the rats nest removal monday and yesterday I tried to fire up the rx7. When i first got it i couldnt pull start it and after messing around in the engine bay found 2 injectors unplugged and 3 sparkplug wires unplugged and misc other connectors. Got them all put back to where they belong and removed the P.O. alarm system. Sprayed just a touch of starter fluid on the filter and she fired up. Ran really rough for a while but it still started.

After letting it run for a while it still wouldnt really idle so I shut her down and let it cool off. grabbed the compression checker and saw 80-85 on the front faces. Figured thats not too bad. Moved to the back and got absolutely nothing. So I guess its time to rip out this motor and import a TII motor.

 

good luck. you may want to rebuild the JDM junkyard engine before you drop it in.

 

Nothing, you got nothing on all 3 faces?

 

Which injectors where unplugged? I say this casue if you were cranking the motor with the injectors working thus flooding the rear rotor. This can lead to false readings. If you have the time try putting a teaspoon of ATF in the rear rotor and run if for awhile. Try the comp test again.

 

Yah i tried to ATF trick on my last rex with great results. I may try it again. the top 2 were unplugged, one for the front and rear rotor. The injectors werent working though, the EFI fuse was pulled. And yes I saw nothing on all three faces. Which is weird because when my first RX7 went it had compression on 2 faces and not the third, I always wondered how it was possible to blow one apex seal and that one not take the other 2 with it?

 

If you lose compression on 1 face, a side seal went out. Losing an apex seal causes 2 faces to no longer have compression. You have to lose 2-3 apex seals to have 0 compression on all faces. But even then, they don't have to physically break or fly out the exhaust ports. A simple dent in the surface will do it.

 

Well its weird because I have NO compression at all. I dont know if its because its not a piston motor but there isnt anything in there.

 

If you have the exhaust manifold OFF the engine,you can Look into the exhaust port and SEE the apex seals,and even Feel them if you roll the engine over,BY HAND..Carefully!..
If they are Not smooth , have Jagged edges or are GONE,then ya,.,the back rotor would have Zero Compresssion!

 

An RX-7.. with a blown motor... NO WAY!

Verify for sure, but rebuild your motor, or at least see what is the problem after a tear down. A blown engine is a great learning experience.

 

Well I dont want to keep this motor. I want a turbo one. Auto-X has pretty much left my area so theres no sense in me building this RX7 for auto-x like I did my last one. Everyone here just goes in a strait line so Im gunna aim for a mid 300 turbo build. I may keep my N/A and rebuild it just so I can say I did it. I just dont think I will even break even. I figure around 1000 for a rebuild and for the N/A motor/trans/ecu I dont know if I can even get 1000 for it.