Guys,

I have a T04R boosted 2 rotor Cosmo motor in my RX8. Stock engine harness has been removed completely, but stock ECU is still in place and still connected to the various other harnesses attached to it. Haltech E6X is running the engine. I have hooked up the renesis crank trigger wheel and sensor to the appropriate 2 pins on the ECU and grounded the appropriate ECU pin in the sensor section to the motor. It is my understanding that doing this should make the stock cluster tach and electric PS work.

Here's the problem; only the PS works. During cranking the tach seems to work (jumps to around 1k rpm), then dies to 0 again. I have the trigger wheel attached to the front of the stock cosmo main pulley and the sensor on a bracket to the front of that. Is there anything else that needs doing? Rgonza (of 20B PR fame) has told me previously that this should get it working. It's driving me somewhat insane not having a tach!

Thanks in advance...

 

Sorry to hijack a little - but I am planning to put my current 2-rotor Cosmo engine (from my FB) into an RX-8 as well. I am going all out with a 2nd 2 rotor cosmo for my FB (600+HP)

I am just curious of how you installed the engine in (mounts). Did you make a new cradle? New Mount? And did the stock intake work fine under the hood?

I would love to see pictures if you got em as well.

Thanks.

-Alex R

 

what crank triger are you using? the cosmo or the rx-8 one? if your using the cosmo trigger wheel can the rx-8 ecu read it?

 

It's the RX8/Renesis trigger wheel and sensor...the PS works fine which is really baffling me as they are both supposedly driven by the same sensor?!

 

First of all, let me commend you for some really big ballz. I think its awesome that you have take on this swap. I don't know that I would have the patience for a lateral swap like that (two essentially identical motors except for the older tech of the Cosmo motor and the FI).

Have you scoped the output of the ESS? Is there a pulse? Both pins (2U and 2X) should show a pulse that follows the teeth of the plate.

I can't say for sure that the ESS is the only way the PCM determines RPM. There is also the speed sensor in the tranny, but I don't know if it matters.
The EPS is more concerned with wheel speed than engine RPM. Have you determined that the other RPM dependant functions are working?

 

demon,

send a PM again to rgonza................
probably he can help you to resolve the problem,
the tach of our cars are working fine.

Manuel

 

I havent confirmed that any other RPM dependant functions work. The VSS in the tranny is not currently connected either (but the speedometer works fine, probably getting from the ABS sensors).

I haven't scoped the output of the sensor yet either; clearly *something* is happening as its disconnection disables the power steering. Do you know if there is anything specific as to how the sensor needs to be mounted? I have it currently mounted pointed towards the front of the trigger wheel rather than to the side of it (if that makes sense).

 

Well, it definitely needs to be pointed at the edge and it has to be really close.
I don't have a chance to mike the distance right now, but I'd say it is around 1mm.
If the sensor is pointed at the front of the plate, the pulses wont be very defined.
Do you have that section of the shop manual?

 

Guess I need to remount this thing...the shop responsible has it facing the front of the trigger wheel probably 1/2" away from it!

 

What kind of transmissions do you have down there?Our Y16M-D Aisin 6 spds do not have speed sensors.

 

Yeah, that won't work.

 

Unusual that the PS even works at all in this configuration...

 

Like I mentioned earlier, I'm not so sure that the EPS actually needs RPM to run.
Try pulling the sensor off of the bracket completely and see what happens.

 

it definetly has to pointed at the edge and spaced only 1 mm like MazdaManiac said .

diagram

 

This is almost certainly the problem. Thanks much for the diagram!

 

since we're on the cosmo subject, i'm doing one right now, with one more on the way as soon as i get done with it

 

oh yea, the wiring diagram is a bit cryptic, but has anyone used something like a pwm output from a haltech to control the tach?