2004 rx8 can not code check no fire
 

I have a 2004 rx8 I got for 500usd the body is meant the inside is meant as well. But the engine I'm new to rotary engines sadly. I have been a mechanic at Subaru for years and Honda before that. So I'm not stranger to vehicles and issues and how to diag. Anyway.... the rx8 I got will turn over no problem. I replaced the plugs because the owner before me had them in the incorrect holes. But it still dose not fire. I have tested the coils and wires with a multi and they check out ok. Tested all the relays as well. All green. When I try and use a code scanner it it says will not communicate with the pcm. So it has to be the computer right? And if so can I buy one offline and install it.. or do I have to take it to a dealer and have it reprogrammed. Or is there a web sight or something I could send it to and could have it done... any and all help is welcome.

Are you seeing no spark, no fuel or both? Are the plugs wet when you remove them form the engine after cranking? Have you verified that you have compression? Does the DLC3 port power up your scan tool?

If you change ECUs you need to bring it to the dealer to recode the antitheft immobilizer.
Its super rare for the computer to die but possible if someone put the jumper wires on backwards.

I'd make sure the fuses and wiring are all OK before going down the ECU change route. You can get an ECU in ebay without too much trouble, just make sure its the same trand and engine config.

I have fuel presser and spark both and compression check came back ok. When it cranks it it sounds like it's not even trying to start just hear the rotors spinning and spinning. The port dose power on my ob2 tester but it's very finicky and u have to move it around to get it to read. But when it dose read it just says can not communicate with pcm :(

The guy that had it before me was a idiot. More then usual of normL car idiot if u know what I mean.. anyway.. he said he was just driving it and it died on the spot and would not restart.

Have you tested compression? It might have thrown a seal. Although the ECU should still connect. Check the connector itself for damage.

Yeah compression test was the very first thing I did... and even if it was compression wouldn't it still read a code of some type? I know how everything works on the vehicle n such. And even in a normal car it should have some type of code. Idk it's got me a little baffled. I am close to just replacing the engine and pcm and being done with it lol

Oops Sidney read all the way lol. My bad. But will.do I'm gonna mess with it here after while and play around with some things

Well the thing is the ECU might be fine and the wiring or connectors to it are damaged. That would be my bet, its hard to kill an ECU. If someone had jumped the car with backwards polarity maybe..

Since even connecting the reader to the OBD plug is finicky, sounds to me like someone messed with it.

Thank u for all of your help