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-   -   Timing errors with AEM EMS-4 (crank sensor) (https://www.miataturbo.net/ecus-tuning-54/timing-errors-aem-ems-4-crank-sensor-71726/)

reddragon128 03-29-2013 03:52 PM

Oh sorry it was the 2000 1.6l protege wheel 36-1 or something that was stickied a while ago and I have a nb crank sensor and nb can sensor.

GAMO 03-29-2013 05:30 PM

Crank sensor: OEM 2002 Miata
Cam sensor: OEM 2002 Miata
Trigger wheel: TSE 12+1

The circuit that I used is the NB Abe circuit but no Schmitt trigger.

reddragon128 03-29-2013 07:09 PM

2 Attachment(s)

Originally Posted by GAMO (Post 995627)
Crank sensor: OEM 2002 Miata
Cam sensor: OEM 2002 Miata
Trigger wheel: TSE 12+1

The circuit that I used is the NB Abe circuit but no Schmitt trigger.

Okay I searched around and found this thread.

Is this the circuit you made? I made some modifications to his picture based on what I understood from your previous post.

https://www.miataturbo.net/attachmen...1&d=1364598557

GAMO 03-29-2013 08:52 PM

That's it: I did it for the cam and the crank.

I didn't have too much time to putz around with the IC since I was trying to make a dyno appointment; however, I found this to work. The guys at AEM were saying to use a pull down resistor, and if that didn't work, try a low-pass. They suggested a max of .01uF, which kind of set me on the wrong path seeing how I was getting RC values of ~.5ms.

reddragon128 03-30-2013 12:42 AM

Wow they told you to do exactly the same things as me. They must have copy pasted the replies to us haha. They were super nice though at least haha so I can't fault them too much.

I can't wait to try the circuit as soon as I get back from the track. Unfortunately running my slow rx8 backup car haha.

Ps: where are you located?

Leafy 04-01-2013 01:51 PM

How bad were your timing errors? I only tested mine during cranking with the injectors turned off before I did the first start of the engine and I was only getting a couple. I didnt have time to go back and look with the car running to see if I was getting any. I think the most I ever saw with the cam/crank sensor diagnostic box pulled up was 3 while cranking.

miatauser123 04-01-2013 06:39 PM


Originally Posted by reddragon128 (Post 995658)
Okay I searched around and found this thread.

Is this the circuit you made? I made some modifications to his picture based on what I understood from your previous post.

https://www.miataturbo.net/attachmen...1&d=1364598557

Is this diagram a little weord or is it just me. I bought a 2.2k ohm resistor for the one labeled 220k right?

reddragon128 04-01-2013 06:53 PM


Originally Posted by Leafy (Post 996395)
How bad were your timing errors? I only tested mine during cranking with the injectors turned off before I did the first start of the engine and I was only getting a couple. I didnt have time to go back and look with the car running to see if I was getting any. I think the most I ever saw with the cam/crank sensor diagnostic box pulled up was 3 while cranking.

I don't really get any before startup, but afterwards it happened every like 5-10 sec. Kinda inconsistent and random, not related to rpm at all. sometimes it would be like a minute wthout any, sometimes one every 2-3 sec.

reddragon128 04-01-2013 06:55 PM


Originally Posted by Dem768 (Post 996512)
Is this diagram a little weord or is it just me. I bought a 2.2k ohm resistor for the one labeled 220k right?

Basically i think the circuit pulls the signal up to 12V before it filters it. That's all.

I think 220k means 220k...you might have to look in the 1/2 watt resistors.

Leafy 04-01-2013 08:57 PM

:dealwithit:

GAMO 04-01-2013 10:29 PM

Seconding what reddragon1234567890 was saying. If it was attached to engine speed, load, or anything it would have been fucking awesome; however, it was intermittent as fuck and messing with the IAC and shit made it sometimes better but also worse.

As for the diagram, it's 220k ohms in parallel with the capacitor (this is an RC circuit/low-pass filter) and is pulled to ground.

I only get 1, maybe 2, timing errors and it's during cranking. A 15 mile drive would net me north of 100 timing errors. It wasn't pleasant.

reddragon128 04-01-2013 11:11 PM


Originally Posted by GAMO (Post 996574)
Seconding what reddragon1234567890 was saying

Lol.

reddragon128 04-02-2013 03:54 AM

Hey Gamo,
I just tried it and things are WAYY better. I got 1 while cranking, and 2 shortly after starting, but i've had the car on for like 20 min now and no more errors! Is that what you're seeing as well? Also do you have your crank set on Hall rising or Hall falling? People say it doesn't matter but I was wondering what you're running. I have Crank Falling and CAM rising.

GAMO 04-02-2013 08:05 AM

Set both of them to the same edge detection, there will be a delay if they are not the same. Also, check the base timing because you might be off a few degrees.

I usually get one or two at cranking, but that's it. I'm glad it's working for you.

miatauser123 04-02-2013 09:16 PM


Originally Posted by Dem768 (Post 996512)
Is this diagram a little weord or is it just me. I bought a 2.2k ohm resistor for the one labeled 220k right?

I just did this and the car won't start now. Feedback?

miatauser123 04-02-2013 09:37 PM

I only did the crank for now.. Not sure if it matters.

Savington 04-02-2013 09:45 PM

Just FYI, 2-3 timing errors during cranking are totally normal.

miatauser123 04-02-2013 09:57 PM

After installing this circuit on my cam and crank without changing any settings I get no startup. Just counts errors and won't fire up. Without the circuit it fires up and will randomly error while at idle and cruising.

JasonC SBB 04-02-2013 10:58 PM

Does tooth number increment?
You probably screwed up and the AEM is getting no signal.

GAMO 04-02-2013 10:59 PM


Originally Posted by Dem768 (Post 996913)
I just did this and the car won't start now. Feedback?

Did you get a 2.2k or a 220k ohm resistor?
Is the crank count incrementing?
Is the cam count incrementing?


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