Mazda Rx7 started misfiring after rebuild
 

Hi, guys, I need some help with my 13b REW 1992 JM1FD, I have rebuilt the motor after rebuilding it's not running okay, it does idle very smooth around 950 to 1000 rpm. when I give it a sudden gas. it does very bad misfiring and doesn't want to Rev up. I did disconnect the trailing spark plug wires in order test the misfire on Leading plug, So it's doing the same. Plus it's running pretty Rich, I have noticed O2 sensor wires were not connected. what could be issue Bad Map sensor?

Engine running
https://www.instagram.com/p/BRLtIatAUEw/

Make sure the vacuum supply to map sensor is connected and that the arrow on check valve in the vacuum hose for the map sensor is pointing towards the engine

Thanks for reply Chrisaleggett, are you sure that a check valve? I thought that black check valve shape thing is just a filter, not an actual check valve, it does bypass air on both ends. And yes right now the Arrow of this filter pointing towards map sensor, not to engine side.

easy to tell if you have it routed right, pull the line off at the sensor and be sure it has vacuum to it.

And check to see if you CAS is hooked up correctly.

https://cimg2.ibsrv.net/gimg/www.rx7...7cbf471897.jpg

Here is the link of engine idling
https://www.instagram.com/p/BRLtIatAUEw/
Yes cas are hooked Okay otherwise it won't start
Any more suggestion, if I Rev slowly it revs higher than again start misfiring with very loud blast, problem seems like ignition timing. What you say

Cas picture
 

Guys I have checked whatever you have suggested, but no luck let me know what else to look for

That's a problem because the arrow needs to be pointing towards the engine.If the arrow is pointing towards the map then the sensor isn't reading vacuum.Just think of the arrow as the direction of air flow, vacuum/pulling air towards the engine. Somehow the valve got turned around.
Flip the valve around and stop running fat. Also be careful not to break the plastic nipple. Good luck let us know

There's no check valve on the MAP sensor. It's a filter

Even though i originally posted it as a check valve I meant filter "Gas filter" But the arrow is there for a reason so direction of the filter should go arrow pointing towards engine.

compression test

did compression test on cold and weak battery it was 75 psi. before rebuild it was 65
 

Hi rotary evolution thanks for your time, I did test the compression on both rotors it was 75 psi on cold engine with pretty weak battery, before rebuild it was 65 psi on hotter engine and it was running pretty fine bro. Only reason for rebuild was blown water seal. I will test the compression for you again and make video. Have you watched my video, in which car is running?

here is the link:

I did test the compression on hotter engine , its giving 90 to 95 psi on both rotors, So Compression is okay. other important information. engine is burning alot of fuel, when ihave removed the plugs, there pretty black. So any more suggestion here?

Was that 90-95 overall? Or all 3 bounces?

overall was 90 to 95 on both rotor, i did test each 3 pulse with hand tested method which are pretty strong and all 3 pulse on both rotor seems equal pressure. bro, earlier this engine was on 65 psi on both rotor and it was starting very late, but when it started once, it revs proper with some normal misfiring, ... right now with new engine after 2000 RMP it starts misfire with huge loud blast, for example a piston engine would do that on wrong ignition timing.

sounds like your map sensor is having issues. check the map sensor, the sensor line all the way and make sure it to the proper port and then check the wiring under the left front fender. if it's rubber through from the tire it usually kills the map sensor signal.