So I have recently got my 99 Miata running on ms2 firmware 3.4. I have been having the problem of when I try to start the car the MS does not see the RPM. I changed some ignition settings and cranking RPM and it started reading RPM every time and started yesterday. I go to start the car this morning and experience the same issue no RPM signal in MS. If I keep trying to start it maybe 1 in 20 times the RPM sync will light up for 1 sec go off and not turn the car on. I am not sure where to go from here. Any help would be greatly appreciated.

 

I can post any info you guys need to know to help out. The tune or a data log if this is not something that is an easy solution.

 

Please take a composite log and post it here.

 

Here is the composite data log I got from trying to start the car. I kept cranking it for about 15 to 20 seconds before stopping.

 

Also I forgot to mention but I did give it some throttle input during the cranking and you will prob see that in the log.

 

I was wondering if there were POT setting for ms2 diypnp like this one.
https://www.diyautotune.com/product/...assembled-kit/

I have seen a few responses from people about POT settings but they always refer it to ms3x.

If so i'm guessing that could be my problem? Just weird that it worked before without having to do anything inside the mega squirt.

 

I am still getting nothing checked some stuff on the board it seemingly checked out with the info i had. I feel like I am stuck. I just dont get why it ran before and doesent now. the car works fine with stock ecu plugged in.

 

So I uninstalled my 5x racing timing wheel and I replaced my old aftermarket crank sensor for a new aftermarket crank sensor. And I am still getting no RPM signal. I am posting my tune and composite log. Any help or suggestions would be great.

 

flip your cam polarity from inverted to normal.

 

Flipped it to normal. And no luck. I put attached another log after I switched the cam polarity. Tomorrow I am going to make sure I did not put my timing wheel in flipped backwards.

 

weird, you stopped getting a cam signal altogether in that log...

in the previous log, your crank and cam had different polarities -- they both need to match.

 

Do you think it may have anything to do with a cheap aftermarket crank sensor? I know the sensor works because the factory ecu runs the car just fine. And I was also suggested that I may of installed the timing wheel in backwards? Could that possibly cause an issue like this?

 

crank signal is coming across fine, you lost the cam signal in that last log. green is cam, blue is crank, red is error (either missing or unexpected)

 

Have any ideas what could be causing that to happen? Is there anyway I could test the cam sensor with a voltmeter? I do have another 99 Miata all stock I could swap the cam sensors and see if that helps do anything.

 

I just made another log. Switch the cam sensor out for another known good sensor and no luck. So I noticed that is it grounded to the intake manifold and I put a thermal intake manifold gasket on it could that cause a bad ground? And could a weak ground give a signal like that?

 

So I did a few more things. I took the ground from the intake manifold and put it right to the frame rail and sanded off the paint for a better connection. I changed the cranking RPM to 300 and it seemed to be lighting up the RPM SYNC light more often then it usually does. But still no start. I took another log and going to attach them here. If anyone could give me some other suggestions on what to do. I may run a wire from the cam sensor right to the MS and see if that is an issue. Is there anything in the megasquirt I can check with a multi-meter to verify that it is correct?

 

 

Update. I checked the orientation of my factory timing wheel that I had to put in due to the though the 5x racing wheel was not lined up perfect. And come to find out the OEM wheel is reversed. In the logs it shows no cam signal but maybe if the crank is not triggering when it things it should it will not show a cam input? Well when I get home I am going to switch it around and hope I get some reading and or get the damn thing running again.

 

The issue is definitely with your cam signal. The signal your log is showing is clearly a crank signal. Have you confirmed continuity from sensor to MS?
In order to further troubleshoot if the error is within the MS or signal going into the MS, you could swap cam and crank signal lines and log crank and cam. If all the sudden your crank signal shows up where your cam is supposed to be, the problem is the cam sensor or wiring. If the cam shows up where the crank is supposed to be, it's a problem inside the MS.

 

So I checked the wheel and all was good. I then de-loomed the wire to the cam and crank sensor and separated them as far apart as I could and it seems to start every time. So now that I can get it started it runs very bad. Does anyone have a good start up tune for a 99 miata? I can find a few but they all have different settings. Or is there something I need to do to get the car to run smoothly.