2004 Mazda Rx8, 6 port
Recently rebuilt the engine
Checked all of the fuses
Checked all of the grounds
Checked the forums for a similar issue with no luck
Everything else is working. Fuel pump works just fine.
Any help would be appreciated.

 

I recently performed an engine swap and had a similar issue. I had spark and fuel pressure but no start. My injectors had gumbed up from sitting for so long. I swapped them with fresh injectors and the car started right up.
Make sure you are getting injector pulse. Check with a test light. Verify you have injectors hooked up correctly. You can check to see if the injectors cycle with a 9 volt battery, listen for a click. Check cel codes. Check maf voltage. Double check all connections.

 

The injectors themselves work fine and are clean. I am checking the pulse with a noid light and I am not getting any voltage at the harness, but i am getting spark.

 

Probably the obvious thing but .................. are you testing the reds only ?

 

No. I have tested every injector connector and i am getting no pulse.

 

Well ............ you should only be getting a pulse from the reds and only when engine is turning over ..................

 

That is correct. I am turning the engine over and I am not getting a pulse from any of the connectors.

 

have you checked all the fuses ?

 

Yes. I have checked all of the fuses, grounds, and the connections at the PCM.

 

next step, if not done, would be check relays and cleanliness of all connections. See attached link for a diagnostics file

http://jmp.sh/wmBjaSc

 

I have checked all of the connections and they are clean. Why would only the red injector connectors emit a pulse?

 

Cause cranking and idle and low load they are the only injectors firing

 

Which is strange because I am using a noid light and checking for pulses while cranking the engine. I am at a complete loss.

 

Check to see if you have B+ at the injector connectors...if you don't you don't have power....

 

Wouldn't the noid light tell me if I have power? If I am not getting power to the injectors but I am getting power to the spark plugs where should I start looking? Thanks for all of the suggestions.

 

No, use a multimeter. The light pen things are pretty much useless 99% of the time IMO. You're not measuring power to the spark plugs with that light btw.

The B+ that was mentioned is a voltage that should match the voltage of the positive terminal of the battery.

 

It's not a light pen. It's an actual injector tester kit rented from autozone. If I am not getting B+ power where should I look first?
Thanks

 

I'd try ohming out the wires from the injector plugs to see if there is a short.

 

The injectors all get power from the same fuse......and the same feed.....they trigger by being grounded...

If you don't have B+ at the injector it means there is an interruption in the circuit...either the fuse....a feed relay...or a problem with the wire itself

 

have you actually checked that there is fuel getting to chambers ? IE are spark plugs wet and do you get a mist when turning over the engine with plugs out .


If so ........... are you sure it isn't just flooded ?

 

So the Renesis HP has 2 Red Injectors and 4 yellow ones, right?
So I should have 2 injectors active on idle, 4 others not.

I connected my computer to the Mazda ECU and it reads that 4 injectors are active. They values are not doubled, each injector has its own value.

How can my Renesis HP run on 4 injectors, 4ms each on 800rpm and have a 42% engine load? It's terribly hard to start, it floods, and it would atleast explain alot. When I add throttle a bit (adding more air) it also start better. When I finally start it, it just sends out a giant cloud of unburned fuel, sputters into the 3000rpm and my neighbours closed their windows from the gasoline smell.





Right here in the same program you can see that at Idle only 2 injectors are active. Why are there 4 active in mine then??? Is it a PCM update or what?

I might strongly consider just disconnecting Primary 2 and Secondary injectors and see how the car starts then. I also get ticking from the engine bay which according to many is a stuck SSV valve. Could it be stuck open and activating the Primary 2 injectors?