Bought a Miata that won't start - Help Troubleshoot
#81
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2012
Location: San Jose, CA
Posts: 144
Total Cats: -3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
The last thing I wanted was for the problem to be a wiring problem and I'm still hoping its not it. I think that instead of still trying to work with the MS, it may be best to get the stock ECU in and hook up the MAF and start working from there right?
Basically, I've taken the car, undone the wastegate, stock injectors are in the car, stock ECU is now plugged in and I plugged the MAF connector into the MAF sensor. Anything else I need to do to have the car "think" it is stock? All I'm trying to do is get it to fire. If I can get it to fire on the stock ECU, then it really narrows down things to the MS being bad (my thought).
The one thing that I did notice when I plugged the stock ECU and MAF in was when I turned the car to 'ON' the fuel pump didn't prime nor was it constantly running like it was when the MS was on.
Basically, I've taken the car, undone the wastegate, stock injectors are in the car, stock ECU is now plugged in and I plugged the MAF connector into the MAF sensor. Anything else I need to do to have the car "think" it is stock? All I'm trying to do is get it to fire. If I can get it to fire on the stock ECU, then it really narrows down things to the MS being bad (my thought).
The one thing that I did notice when I plugged the stock ECU and MAF in was when I turned the car to 'ON' the fuel pump didn't prime nor was it constantly running like it was when the MS was on.
#82
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Yeesh, and I thought the wiring in my car was a mess.
BTW, I would suggest not trying to engage the starter with that braided ground wire missing between the block and the chassis. As I understand it, that's the ground that all of the starter current uses to get back to the battery, and if it's gone then it's going to find other ways to get there -- like through your ECU.
--Ian
BTW, I would suggest not trying to engage the starter with that braided ground wire missing between the block and the chassis. As I understand it, that's the ground that all of the starter current uses to get back to the battery, and if it's gone then it's going to find other ways to get there -- like through your ECU.
--Ian
#83
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2012
Location: San Jose, CA
Posts: 144
Total Cats: -3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Yeesh, and I thought the wiring in my car was a mess.
BTW, I would suggest not trying to engage the starter with that braided ground wire missing between the block and the chassis. As I understand it, that's the ground that all of the starter current uses to get back to the battery, and if it's gone then it's going to find other ways to get there -- like through your ECU.
--Ian
BTW, I would suggest not trying to engage the starter with that braided ground wire missing between the block and the chassis. As I understand it, that's the ground that all of the starter current uses to get back to the battery, and if it's gone then it's going to find other ways to get there -- like through your ECU.
--Ian
#85
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2012
Location: San Jose, CA
Posts: 144
Total Cats: -3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Hooked the ground back up to the ground plate.
Tried to check spark and I didn't see anything. Even when switching between the two sets of coil packs no difference. First I want to see if I even have this setup and grounded the right way
IMG_20130804_133732_zpsd9c83411.jpg?t=1375649238
IMG_20130804_133744_zpsb2a588b0.jpg?t=1375649247
Tried to check spark and I didn't see anything. Even when switching between the two sets of coil packs no difference. First I want to see if I even have this setup and grounded the right way
IMG_20130804_133732_zpsd9c83411.jpg?t=1375649238
IMG_20130804_133744_zpsb2a588b0.jpg?t=1375649247
#88
Boost Czar
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/admin.png)
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,688
Total Cats: 4,113
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
was the above on the stock ECU or MS? Like I said in one of my first posts, no spark typically = equals no CAS or a bad ignitor.
where does the wire that goes into the o2 connector go?
what about the one in cabin? is that the wire grounded or the wire on the add a fuse?
really need to know exactly where this wires connect and terminate at.
where does the wire that goes into the o2 connector go?
what about the one in cabin? is that the wire grounded or the wire on the add a fuse?
really need to know exactly where this wires connect and terminate at.
Last edited by Braineack; 08-05-2013 at 08:07 AM.
#89
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2012
Location: San Jose, CA
Posts: 144
Total Cats: -3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
The above is with the stock ECU now. I want to first get the car to fire with stock ECU and then we can work on the MS from there.
Hooked up the MAF, installed stock injectors and the stock ECU. I checked voltage on the one you told me to check and then I also checked it on the ECU to ensure I'm getting 12V on 1B when the key is ON and I get it. So I'm thinking we can rule out the ECU not getting power.
I have replaced the CAS with another CAS that I purchased to no avail. The only thing that I am going to end up checking is to possibly see if for some reason the timing belt jumped teeth and is a reason why the car won't start (wouldn't that be funny if this is the reason) In addition, I thought there wasn't a way to mess up the CAS install but what I did was I removed my valve cover (I know you don't need to, but easier) pulled the old CAS and then just put the new one in the only way that it was able to go in (matching it up to the indentation of the cam). Was this not the correct way to install it?
Braineack, I checked all the wiring that you asked me to check. You can check Post 78. (https://www.miataturbo.net/general-m...4/#post1039653). Since then, I've added a ground from the grounding block under the brake booster to the motor point.
Hooked up the MAF, installed stock injectors and the stock ECU. I checked voltage on the one you told me to check and then I also checked it on the ECU to ensure I'm getting 12V on 1B when the key is ON and I get it. So I'm thinking we can rule out the ECU not getting power.
I have replaced the CAS with another CAS that I purchased to no avail. The only thing that I am going to end up checking is to possibly see if for some reason the timing belt jumped teeth and is a reason why the car won't start (wouldn't that be funny if this is the reason) In addition, I thought there wasn't a way to mess up the CAS install but what I did was I removed my valve cover (I know you don't need to, but easier) pulled the old CAS and then just put the new one in the only way that it was able to go in (matching it up to the indentation of the cam). Was this not the correct way to install it?
Braineack, I checked all the wiring that you asked me to check. You can check Post 78. (https://www.miataturbo.net/general-m...4/#post1039653). Since then, I've added a ground from the grounding block under the brake booster to the motor point.
#91
Boost Czar
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/admin.png)
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,688
Total Cats: 4,113
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Braineack, I checked all the wiring that you asked me to check. You can check Post 78. (https://www.miataturbo.net/general-m...4/#post1039653). Since then, I've added a ground from the grounding block under the brake booster to the motor point.
I noticed in your pics the ignitor was unplugged, when you tried testing for spark, that was plugged in, right?
#92
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2012
Location: San Jose, CA
Posts: 144
Total Cats: -3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I saw the post, you didn't clearly follow through and why I wanted clarification. Just saying, there's a wire in my o2 connector tells me nothing. I KNOW there's a wire in your o2 connector, where in the bloody **** does the wire go to?! same thing with the two at the fuse box. i see one is grounded and looks to go into the cabin, where do it go EXACTLY?! and the one with a fuse, where exactly does the black wire after the two little zip ties go?
I noticed in your pics the ignitor was unplugged, when you tried testing for spark, that was plugged in, right?
I noticed in your pics the ignitor was unplugged, when you tried testing for spark, that was plugged in, right?
In regards to the two wires at the fuse box I thought I called it out in my post, but it goes into the cabin and then looks to be into the back of the aftermarket deck. The wire that goes into the cabin is a speaker wire (two separate wires "jointed" together). This wire is the same wire that has the add-a-fuse.
1. 0:00-0:10 - Some black wire that leads into the cabin.
- This goes into the cabin and then looks to be into the back of the aftermarket deck. The wire itself looks like speaker wire.
2. 0:10-0:20 - Add-a-fuse into the main fuse box.
- Same as above, there is a terminal that goes into the fuse box and then that wire is fused and then the wire is the black wire that leads into the cabin as noted above. The other wire goes to a ground
When testing for spark, yes I plugged in the ignitor module.
#94
Boost Czar
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/admin.png)
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,688
Total Cats: 4,113
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Maybe I'm not understanding it clearly but there is a wire that comes from the main wiring harness, goes into the connector and then from the other side of the connector comes another wire which leads to my O2 sensor. If you're looking for me to follow where the wire is coming from in the main harness, then I haven't checked that yet and I'll have to unwrap the main wiring harness to trace it back to the source.
In regards to the two wires at the fuse box I thought I called it out in my post, but it goes into the cabin and then looks to be into the back of the aftermarket deck. The wire that goes into the cabin is a speaker wire (two separate wires "jointed" together). This wire is the same wire that has the add-a-fuse.
1. 0:00-0:10 - Some black wire that leads into the cabin.
- This goes into the cabin and then looks to be into the back of the aftermarket deck. The wire itself looks like speaker wire.
2. 0:10-0:20 - Add-a-fuse into the main fuse box.
- Same as above, there is a terminal that goes into the fuse box and then that wire is fused and then the wire is the black wire that leads into the cabin as noted above. The other wire goes to a ground
When testing for spark, yes I plugged in the ignitor module.
1. 0:00-0:10 - Some black wire that leads into the cabin.
- This goes into the cabin and then looks to be into the back of the aftermarket deck. The wire itself looks like speaker wire.
2. 0:10-0:20 - Add-a-fuse into the main fuse box.
- Same as above, there is a terminal that goes into the fuse box and then that wire is fused and then the wire is the black wire that leads into the cabin as noted above. The other wire goes to a ground
When testing for spark, yes I plugged in the ignitor module.
that doesn't make sense.
![](https://www.miataturbo.net/attachments/general-miata-chat-9/84959d1375712751-bought-miata-wont-start-help-troubleshoot-wiring.jpg)
one wire (pink) clearly goes to a terminal and is grounded. the other (green) is connected to 12v and it's not clear where it goes.
I only see one wire going into the cabin.
#95
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2012
Location: San Jose, CA
Posts: 144
Total Cats: -3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Ok here is a better picture showing what's happening. Let's start from the speaker wire which is coming from the inside of the car into the engine bay. From this picture, you can see the speaker wire splits into two paths. Path 1 takes it straight to the ground. Path 2 takes it into the add-a-fuse and then into the fuse box. Hopefully this picture is clearer.
IMG_20130805_081719_zps42001ac0.jpg?t=1375715924
![](https://www.miataturbo.net/attachments/general-miata-chat-9/84964-bought-miata-wont-start-help-troubleshoot-untitled_zps17394092.jpg?dateline=1375716279)
Then this connector (not the plug for the coils) is the single wire going into that connector. That connector on the other side then leads a line into my O2 senor on the downpipe.
IMG_20130805_081719_zps42001ac0.jpg?t=1375715924
![](https://www.miataturbo.net/attachments/general-miata-chat-9/84964-bought-miata-wont-start-help-troubleshoot-untitled_zps17394092.jpg?dateline=1375716279)
Then this connector (not the plug for the coils) is the single wire going into that connector. That connector on the other side then leads a line into my O2 senor on the downpipe.
![](http://i42.photobucket.com/albums/e338/HardHitter2k4/IMG_20130714_114404_zpsdb6b6513.jpg)
#97
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2012
Location: San Jose, CA
Posts: 144
Total Cats: -3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I understand everyone's concerns of how shitty the wiring is in this car and it is my concern as well. The only thing I don't understand is that this car ran fine on the MS, got dynoed and he drove the car and then all of a sudden the car just stop firing when cranking. To me, no matter how shady the wiring is, if it worked before then the car is wired correctly, but something either came loose or something mechanically no longer works.
I think that right now, knowing that the car isn't getting any spark is the key problem to search down. I don't know if it's my plugs, plug wires or the coil pack itself. Or potentially the wires going into the coil pack.
#99
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2012
Location: San Jose, CA
Posts: 144
Total Cats: -3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I would agree with you on that Chris as being the first and cheapest route to check. I would be able to check that by measuring volts at the plug that plugs into the coil pack correct? If I have 12V at that point, then it would rule out the signal not getting to the coil pack to tell the plugs to fire.