I was going throught the process of making the wiring harness for the Ultimate for my 96 again and when I was looking at the wiring diagrams trying to figure out which wires i should use for the crank and cam angle sensors I realized I had no idea which ones I should use.

I searched around on here and the only information that I could find was a thread about someone that couldn't get their car to start and was told to disconnect the cam and crankshaft angle sensors from the E-manage and to just use the rpm signal. this left me more confused especially since I thought that using either the crank or cam angle sensors would be more accurate than using just the rpm signal since they should give you better resolution.

Just to coplicate it allittle more I also read a thread that mentioned that the crank sensor teeth are unevenly spaced and is mainly used to detect detonation for the OBDII engines; which makes me think that it might not be easy to get the EMU to read it properly without letting it know the angle between the teeth. So this at least would make me think that the cam angle senor would be the one to use but if so how should it be hooked up? There are two signal wires coming from the cam angle sensor one that gives you 2 pulses per cam rotation and the other that gives you 4 but there is no indication of what the E-manage would expect to see for either the crank angle sensor or the cam angle sensor.

Needless to say I'm hoping that someone can help me stop torturing myself with these details with some information that makes things more clear, so I can stop doing this

 

It is not necessary to connect the cam and crank sensors to the EMU. It is sufficient to pass the injector and ignition signals through it.

 

Joe explained what is going on in the ultimate in a bit more detail in this post.

https://www.miataturbo.net/megasquir...94/#post329077

From what I read, Emanage uses the period and rate of change of the injection/ignition signals as the timing base when calculating fuel and spark adjustment as opposed to using crank and cam signals.

 

I was previously worried about this mainly because I was under the impression that my car was batch fired and was hoping to use the EMU to convert to sequential injection. However I previously found out that my car is already sequential thanks to this forum.

It does make me wonder if any one with a batch injected 1.6 car would be able to use the EMU to switch to sequential injection without a crank trigger wheel by using the CamAS.

Thanks again for helping me sort out my EMU issues.

 

As a former EMU owner, I'd be curious to know why anybody with a '90-'93 car was using one in the first place.

I can see a hypothetical argument in favor of the EMU for '96 and later cars in states with plugin OBD-II emissions testing, but for a '90-'95 car, I cannot imagine any reason at all why I would go back to one.

 

It looks like to derive sequential injection from batch then both crank and cam signals need to be wired to the EMU.

Vehicles with simultaneous and grouped injection that has cam and crank angle signal can be changed to sequential injection by configuring the input and output signal. To change the injector channels, set the output channel number, activate the each channel and set the injection timing (Section 8 in operation manual.)






It looks like it is also possible to use crank angle as the primary rpm input.





I am curious to know if fuel and spark timing is calculated differently by EMU when crank angle is selected instead of tach output as the EMU rpm input?

 

I'm running both RPM and crank+cam signals on a NB FL.
I had no issue over there, while previously I couldn't turn another car on (it was another NB FL IIRC)
I was VERY surprised when the 2nd one started running. Wiring was done by the same guy for both, and I'm 99% sure it's correct on both cars. I will re-check it, of course.

I can try on that car if there's any difference. Theoretically speaking, the way of tuning the car with the software shouldn't change.