No spark on start up with VVT swap
#1
Elite Member
Thread Starter
iTrader: (8)
Join Date: Jan 2012
Location: Tampa, Florida
Posts: 2,568
Total Cats: 217
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Rev built me an MS2e back in 2013 for my MSM. All of the wiring was stock. I just completed a vvt swap and am having trouble getting the car started. There is no spark and I cannot figure out why. I am using stock 01+ semi cop coils with the stock wiring. I did have to extend the wiring for the cam sensor because the MSM cam sensor is on the front of the head and reads from the cam gear while the VVT came sensor is on the back of the cam cover and reads from the teeth on the back of the teeth on the cam itself. I was wondering if anyone could take a look at the attached log and see if they can see anything that might cause this as everything else seems to be working just fine. I did change the setting in 'ignition settings' to use cam sensor reading if available to 'on'. It was previously 'off' but neither setting worked. Any help would be greatly appreciated.
#3
Elite Member
Thread Starter
iTrader: (8)
Join Date: Jan 2012
Location: Tampa, Florida
Posts: 2,568
Total Cats: 217
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I went back over the wiring for the cam sensor and I know the ground wire and the power wire are working. I have not been able to figure out how to test the signal wire connections yet but Sixshooter is coming over with his multimeter now. I also respaced the crank sensor because it was bothering me. I have attached a composite log to show what I am seeing. It definitely does not look right to me but I am at a complete loss.
![](https://www.miataturbo.net/attachments/megasquirt-18/133257-no-spark-start-up-vvt-swap-composite%2520log%2520ryan_g_zpsoewqxwao.jpg?dateline=1423947377)
I know that each of those red lines is also the recording of an event that the computer did not expect. Any ideas?
![](https://www.miataturbo.net/attachments/megasquirt-18/133257-no-spark-start-up-vvt-swap-composite%2520log%2520ryan_g_zpsoewqxwao.jpg?dateline=1423947377)
I know that each of those red lines is also the recording of an event that the computer did not expect. Any ideas?
#5
Elite Member
Thread Starter
iTrader: (8)
Join Date: Jan 2012
Location: Tampa, Florida
Posts: 2,568
Total Cats: 217
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Been trying to fix this all day. I have attached some a new data log and the latest composite log. After doing some more research, I think the cam and crank signal may be correct the way they are now but I am not sure.
#6
Senior Member
iTrader: (1)
Join Date: Sep 2011
Location: Lambertville, NJ
Posts: 1,215
Total Cats: 74
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Your CAM signal looks as expected, but your crank signal is all whack. Should be all single peaks. Your signal stays up, goes down and is in general unpredictable.
I'm not familiar with your particular MS, but if you're sure your crank angle sensor works OK and your wiring is done well, you may have to adjust the input sensitivity on the MS in some way. My MS3 has a potentiometer for that.
You could also post a composite log (*.csv) for further troubleshooting.
I'm not familiar with your particular MS, but if you're sure your crank angle sensor works OK and your wiring is done well, you may have to adjust the input sensitivity on the MS in some way. My MS3 has a potentiometer for that.
You could also post a composite log (*.csv) for further troubleshooting.
#8
Elite Member
Thread Starter
iTrader: (8)
Join Date: Jan 2012
Location: Tampa, Florida
Posts: 2,568
Total Cats: 217
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
The cam signal was disabled from when I was driving it around and to my knowledge has always been that way. However, I did enable it and tried that as well and there was no change. I believe the crank sensor is good as it was fine on the car before it exploded so unless I just got really unlucky and it died somehow while it was off the car I don't think that would be the problem, but not impossible.
#15
Moderator
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/moderator.png)
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,884
Total Cats: 3,075
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Maybe someone else with an NB could post pictures of their timing marks and you could see if the trigger tooth that is just to the right of them on your car is just to the left of them on someone else's.