[SOLVED] Startup behaviour (no crank)

I am currently working on a project car, taken the engine out of a CX7 2.3 and putting it into an mx5 mk 3 (same year)

I have replaced the wiring harness in the MX-5 with the one from the cx-7 along with the dash and ecu.

Coming to the end of the project now and attempted to start the engine yesturday but had no crank and thus wont start.

Battery was showing low voltage (10v with ignition set to on, 11.8 with it off) and kept losing its charge when not even installed in the car so I replaced the battery with a new one, again still no crank.

As I have adapted the harness a few times to fit with the centre console of the MX5 I have made some changes - as I only drove the donar car twice before pulling the engine I am not sure of the start up behaviour of this car.

Does the radio cut out when the key is in the start position? I am wondering if I have a short or a bad ground, as when I turn the ignition on, my radio does turn off and comes back on straight away after I put the key back to ignition on.

Another thing that I want to confirm, just on the off chance that I am missing something, if the key is not recognized, should there be a red key icon flashing on the clock display? I have used forscan to add the MX5 keys, its saying there are now 4 keys programmed and the red key light is off when that key is in the ignition.

Further to that I do have a couple of error codes, but wouldnt thought they would cause the engine not to run?
First is a known issue with the front crash sensor communication error (fixing this soon) and the second is rain sensor issue (I removed it for this project)

Diagnostics I have done so far, I have tested the main 150A fuse to the starter and thats fine, while I have not fully tested the relays I can hear them click so it sounds like the start key position is working and probably got a good relay.

Next step is to try and check down at the starter motor to make sure I havent pulled the control wire from it - though I have not touched the wiring harness on the engine side it may of came lose/out, just an absolute pain to get to with the size of the MX5 engine bay.

So with that said, if anyone can confirm the radio cuts out on turning the key to start position or if anyone else has any other ideas I would be most grateful.

 

Can't say for certain on the cx7 but I don't think I have ever been in a car where the radio didn't cut out when starting

If there was a security issue with the key you would get the red flashing light. You could always put the cx7 keys near the ignition while starting to check

 

Into the unknown here with this build. I really think the immobilizer is obviously detecting a fault.

Radio cutout is normal when starting though.

Make sure you have spark, fuel, and ground. I know there is a small ground wire next to the hpfp that will prevent startup if not connected.

 

Just thought I would update here in case anyone finds this, a possible sollution, was for me anyway, it looks like a bad connector somewhere.

So I had took the common connector 21 out (the one inside the fuse box, tested the other wires, they all came back ok, took of the control wire and re-attached it, a combination of this got the starter working.

Turns out I done a rookie mistake, one thing I didnt consider swapping out was the starter motor to the MX5 one, though I had swapped the flywheel, the starter motor just current freewheels at this point, will be replacing it hopefully soon.

 

Do you have any pictures of this project?

 

Id like to see some visuals too. Ive entertained putting a KL-ZE or MZR into an NA Miata.

 

For pictures, I have a build post over at mx5 owners club forum, https://forum.mx5oc.co.uk/t/my-current-project-nc-mps-conversion-now-with-pictures/137980

 

Update: Thanks to you guys and advise over the 3/6 subforum the engine starts and runs!

Few things I need to tighten up and adjust but its a good day when an engine thats swapped cars and been sat for over 12 months starts!

Turns out there was 3 things that was causing the issues for it not to start
1.Starter motor had siezed up
2. Injector ground was not connected
3. throttle body connector wasnt all the way on from the looks of things.

 

Awesome it's working!