hello. i recently had the engine rebuilt and now i was left to the taske of putting it back together once the engine was installed and it has. So no ive hooked up all connectors and new battery. car cranks now but will not start. I found out that the obd2 does not work and fuel pump does not prime and radio does not work. I have checked all fueses and tested all relays. I know if the car isnt getting fuel it wont start. im gonna try a little starter fluild in the intake....but anyone have any other ideas that can help. 2005 mazda rx8 A/t. thanks everyone.

 

The room fuse in the drivers side footwell will often make the OBD not work... and the ecu won't get power... so the car won't run

Check all the fuses again...

 

i tested the connection to the fuel pump and its reading voltage. so may be a bad pump. i sprayed starter fluid and that did nothing just cranked. im trying to find my bit for spark pliug to see if im getting spark. and obd is getting no power stiill

 

Ok. I will. I also took out the fuse in cabins and probbed cxn and it was reading but only on one side. As for the fuses ill will double check again. Thank you

 

This may be helpful, maybe not.
Worked for me once.

Scroll down to the immobilizer section, if it's turning over this may not apply, but maybe some of the other troubleshooting issues could be helpful.

https://www.rx8club.com/series-i-do-...utputs-155947/

 

OK. JUST GOT IN and i checked and in fact replaced every fuse with a new one. and it still wont work. im stumped. ill check on the link you sent thank you

 

OK. JUST GOT IN and i checked and in fact replaced every fuse with a new one. and it still wont work. im stumped. ill check on the link you sent thank you

 

i re routed the obd port to a power source but it comes on but no communication is there a way to to connect the two grounds and the main computer just to seee whats going on.

 

I assume you inspected the port to ensure all the pins are intact?

 

yes i did . made sure they where all not spread appart. i took a multi meter to the pin 16 and no power. i checked all my fusesing inside and out. and even changed all the ones in the cabin. still obd was not getting power. i then routed a fused power to pin 16 and plugged in my obd scanner and it powered on. but i dont think the neg and the pin 2 are communicating with the car. whats your thoughts.? thanks for responding so quick.

 

That's getting into unfamiliar territory for me.
I'm not skilled at electrical troubleshooting.
My only suggestion might be to try another OBD port if the wiring isn't a challenge.
If there's a plug in connector it might be worth a shot.

 

Not sure about the radio, but for the fuel pump did you happen to remove the emissions secondary air pump? Some people remove these and the tube that goes to the exhaust manifold while they have the engine out. On the bracket of the secondary air pump should be a fat resistor pack for the fuel pump.

However you said you are seeing voltage at the fuel pump, I do not familiar enough with the circuit to know if the resistor module being removed would prevent you from reading any voltage.

I do know that if you remove the resistor pack you will be able to crank and sputter the engine but not start.

 

You don't want to try and back feed the power to the ECU like that. If the OBD isn't powering up figure out why.... before you blow something up..

 

as i stuck my contorted body i could see there was some wires that showing wire, could short out so i bought a brand new obd port and will fix the wires and not back power it like you suggested. im wonderin also if i have have some kind of short to grounding problem since raidio , fuel pump doesnt prime....any thoughts...

 

OBD port and radio and power mirrors and some other things are all on the room fuse.

The room fuse is fed from the BTN fuse under the hood ....

Make sure you test the fuses with a meter... sometimes they look OK and aren't 🙄

 

sounds like the Canbus wiring might be busted or ground out somewhere

 

Donobre i have not found out the issue on why it wont power on.

 

Have you checked the ignition switch?

The things that werent working are all powered off the IGN 1 circuit

 

no but ill try that tomorrow...thank you

 

in testing do you mean the contact points??

 

Check the wire coming off the switch to see if it gets power with the key on. Do you have a wiring diagram?

 

you know something. I forgot all about the ignitiion condenser. i had a snapped plug and the other part was missing under the MAnifold. I read that it can cause all kinds of issues. on an rx7 the ecm,pcu and a host of other issues stop car from starting. and i just read some on the rx8. I forgot as its taking so long to come. I just reached out and its coming. My appologies. maybe this will help this issue. ill keep you posted.

 

sorry Donobre for wasting time. I turn on the ignition and all the dash lights up and even the check engine which is supppose to mean it has connection with the computer right. but this Condensor seems a key as well.

 

The condenser won't make it not start. Its more of a filter and isn't necessary for spark functionality

What you need to do is get a very detailed look at a wiring diagram... and then start tracing power in the circuuts you dont get oroper oower in. Hioefully rhen you will be able to find where the breach is.

Fuses, relays, and even wire runs could be causing this... you just need to.logically go looking to figure it out

 

aw man here i was excited...lol. but your are very versed in the rx8 world. I have identifix. I know this sounds lame but what wiring diagram am i looking for all of it? i can do that as well.