Wiring Hall Effect sensor?

http://www.diyautotune.com
Post Reply
tchida14
240sx Wannabe
Posts: 100
Joined: Sun Aug 25, 2013 7:16 pm

Wiring Hall Effect sensor?

Post by tchida14 »

Well tonight I went for a ride in my truck with the intercooler piping in there and everything ready to go. I was doing some rough tuning of the maps and all was going pretty well. I stopped at my girlfriends house and when we go to leave, the damn thing won't start.. Come to find out that again, I am not getting a tach signal. I have pin 24 going to the G/Y wire (on the wiring harness side) in this diagram:
Image

it is a 94 hardbody but on DIY's site, it says that the older wiring schemes were retained longer with hardbody's http://www.diyautotune.com/tech_article ... _240sx.htm

The thing is, I am using the G/Y wire for a tach signal since i went distributorless, and it worked for me even though it says it's the G/B wire that should be the ms trigger! Should I simply just try switching the signal wire to the G/B?

I want to do away with the stock wiring harness and ecu as much as possible, is it feasible to just wire the sensor with a switched 12v source to the B/W on harness side, the G/B to ms, and the black grounded with the rest of the other ms grounds on the engine? or connected to the black of pin24?

I still don't get why it worked, and now it's not working... Tomorrow I will go over there and try switching it to the G/B wire and see if that solves my issues.

Really need the help guys... The truck is sitting at my girlfriends place, and we are moving out to college SATURDAY
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Wiring Hall Effect sensor?

Post by Matt Cramer »

You mentioned you went distributorless. What sort of trigger wheel are you currently using? Some of them flip which signal does what.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
tchida14
240sx Wannabe
Posts: 100
Joined: Sun Aug 25, 2013 7:16 pm

Re: Wiring Hall Effect sensor?

Post by tchida14 »

Matt Cramer wrote:You mentioned you went distributorless. What sort of trigger wheel are you currently using? Some of them flip which signal does what.
The 54mm nissan bolt in trigger wheel for the distributor. It worked fine before. New sensor.
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Wiring Hall Effect sensor?

Post by Matt Cramer »

Ours doesn't swap the signals, but it does mean you end up using the second trigger output as a cam signal.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
tchida14
240sx Wannabe
Posts: 100
Joined: Sun Aug 25, 2013 7:16 pm

Re: Wiring Hall Effect sensor?

Post by tchida14 »

Matt Cramer wrote:Ours doesn't swap the signals, but it does mean you end up using the second trigger output as a cam signal.
Okay, but that still doesn't explain why it worked but all of a sudden I go to start it again and no signal.. now that I think about it, when it was driving for the short amount if time it was, there was one point where I was just cruising and it stuttered like I burned a table, but I noticed after start enrichment turned on.. Then later on it was stuttering quite a bit, as if the signal was slowly cutting out more and more..

I was checking the wiring when it happened and I didnt see any fried wires or anything obvious that came disconnected or anything like that, so it makes me think that possibly a relay or fuse could cause this, but everything else is still working. One weird thing is that the fuel pump fuse kept going out when I was trying to start it. The coil pack is run off the fuel pump relay.

What I want to do for a more reliable solution, is return the 12-1 distributor trigger wheel and the $110 ckps, and get your 6 1/2" 36-1 crank trigger wheel and hall sensor, Matt. Simple 12v power supply and white and black go to white and black of the shielded signal wire in the harness. That will work with the hall effect input circuit as well as the vr sensor circuit, correct?

I am curious as to what you think may be my problem here.
I'm looking forward to hearing from you, Matt!
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Wiring Hall Effect sensor?

Post by Matt Cramer »

If this is a regular MegaSquirt and not something plug and play, I'd try testing its RPM input on a Stim at this point.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
tchida14
240sx Wannabe
Posts: 100
Joined: Sun Aug 25, 2013 7:16 pm

Re: Wiring Hall Effect sensor?

Post by tchida14 »

Matt Cramer wrote:If this is a regular MegaSquirt and not something plug and play, I'd try testing its RPM input on a Stim at this point.
Yes it is just a MS2 V3.0. I will try testing it when I go visit home in a few weeks since i'm 150 miles away at college now. I feel like something(flux) must have shorted out on the board because i never cleaned the areas after soldering new features in there, such as the extra spark out put. Seems kinda stupid and naive, but I decided to throw parts at it in an attempt to get it running before leaving by installing your 36-1 wheel and sensor, and even that isn't picking up with the hall input. So it's gotta be something ms related.. Might be as simple as some acetone and a pick to get the flux off, I hope. I emailed you recently about it, i'm not able to use the Vr, and there is a pull up wired on the board for the input.


Thank you for the response, Matt. I will get back to you on here when i test it.
tchida14
240sx Wannabe
Posts: 100
Joined: Sun Aug 25, 2013 7:16 pm

Re: Wiring Hall Effect sensor?

Post by tchida14 »

Hi Matt. I finally got to testing and cleaning my ms with my stimulator v2.2. All the inputs work, and the rpm only works when you set the spark mode to basic trigger. When I change it to toothed wheel it will not show any rpm signal. I didn't check to see if I was getting a signal with the basic trigger setting before cleaning it, but it is working now. That is normal that it won't pick up a missing tooth wheel configuration on the regular stim correct? I guess my next step is to plug it in and see if she runs.
tchida14
240sx Wannabe
Posts: 100
Joined: Sun Aug 25, 2013 7:16 pm

Re: Wiring Hall Effect sensor?

Post by tchida14 »

I just got done hooking up the ms, and I can't see an rpm signal while cranking. I used the settings for the 36-1 wheel like the website says to, and everything seems right, but it's just not working and it's really frustrating me at this point because the rpm is working using the stim with the basic trigger setting. Also, one of the legs on my bip373 mounted to the top cover broke with none of the pin sticking out to resolder a wire onto, so I need a new one of those too... :angry-teeth: But that's a whole other problem.

I am going to try and see if I can get a friends ms2 over here to test and see if it will work with the VR circuit, since he didn't mess up one of the vr circuit transistors like i did... lol

Edit: Turns out my buddy didn't even install the vr circuit, so i am stuck. I am wondering what my next step in the troubleshoot process is? Nothing on the board is fried or anything weird like that, there is no flux build up anymore, and everything seems to work fine in TS. Is there any way I can send my ms unit to you, Matt, to get Q23 in the vr circuit repaired to see if using the vr circuit with the 36-1 wheel will work instead? I'm pretty desperate at this point :(
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Wiring Hall Effect sensor?

Post by Matt Cramer »

The V2.2 Stim can't simulate a toothed wheel, just basic trigger. It sounds like the input circuit in the ECU is working. I'd try spinning the distributor by hand with the key on and engine off, and check what voltage it's sending to the MS.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
tchida14
240sx Wannabe
Posts: 100
Joined: Sun Aug 25, 2013 7:16 pm

Re: Wiring Hall Effect sensor?

Post by tchida14 »

Matt Cramer wrote:The V2.2 Stim can't simulate a toothed wheel, just basic trigger. It sounds like the input circuit in the ECU is working. I'd try spinning the distributor by hand with the key on and engine off, and check what voltage it's sending to the MS.
I didn't see this until after I sent you an email matt, sorry.

I am back at college now so I won't be able to test it for another month, but what should I be seeing for a voltage? I did some research in my FSM and made this. Image

Correct me if my information is incorrect but I should be connecting pin 24 to the G/Y wire for the megasquirt to see the inner ring of slits on the 12-1 wheel. I am also unsure of the grounding and shielding of the CAS signal. Where does it need to be grounded/with what? And does the shielding wire need to be soldered to anything?

Edit: On the second text box I meant to say ECU pins 31 and 40
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Wiring Hall Effect sensor?

Post by Matt Cramer »

The REF signal should go from 0 to 12 volts and back again. You may need to spin the distributor slowly to be able to see the individual pulses.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
tchida14
240sx Wannabe
Posts: 100
Joined: Sun Aug 25, 2013 7:16 pm

Re: Wiring Hall Effect sensor?

Post by tchida14 »

I finally figured out my simple issue. Wrong resistor for the 12v pull up.. :doh: I guess I will rely on the bands of the resistor and not an ohm meter next time since I apparently don't know how to read one lol. Replaced the resistor and then I just had to get my distributor back in and figure out the timing since I switched to a 36-1 wheel and hall sensor from DIYautotune. First time cranking the engine to actually start it, it slowly turned over followed by a huge BOOM out of my open downpipe, scared the **** out of me. So then I took the 1st spark plug out to get the engine to TDC and reposition the rotor and then she fired up right away. I then got the timing light out and got it all synced up with megasquirt and did some initial tuning and went for a drive!! It felt great getting the truck out on the road again but I ran into another issue saturday. When the engine was completely warmed up it would keep losing sync according to datalogs (lost sync reason 2). So I did some googling and found that many people had that issue and people would say that it is caused either by noise in the signal, or the sensor isn't close enough. I looked at my sensor, and realized it was not perfectly squared up with the wheel, but well within the 5mm distance at 2.75mm. I straightened the sensor out with a simple zip tie and haven't had an issue since! I didn't get to drive it a lot but I was doing some pulls at about 80%tps and getting pretty close to full boost.

Thank you Matt helping me troubleshoot and for helping me realize I need to check the simplest of things first!
Post Reply