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L28et Megasquirt 3.57 and 36-1 trigger wheel help


s30kid

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Hey guys S30Kid here AKA Sam and I am stuck in a rut at the moment. I cant get an RPM signal with my 36-1 trigger wheel/Hall sensor that I purchased from DIYAutotune.com.

 

The motor is a f54 n47 combo. 440cc supra injectors, ported intake manifold, 60mm TB, stock 280z distributor and ignition stock turbo, 2.5" down pipe, Mishimoto FMIC, Megasquirt 3.57 and relay board in fuel only. I found out really quick that if you boost 8psi on 280z stock ignition you will break pistons... So now the motor is freshly rebuilt and my dad had some fun with the head. The head has been de-linerd and port matched to the exhaust manifold with polished combustion chambers. 

 

So now I have decided its time to setup the ignition because I do not want to blow the motor again.. I have the wheel and hall sensor mounted. (6 teeth ahead of the sensor) and I will attach a screen shot of my ignition options/wheel decoder. Cranking rpm is set to 300.

 

The plan is to run the 36-1 wheel for my rpm/tdc sig, lock the distributor and fire the coil directly with megasquirt with the distributor only directing the spark.

 

At the moment I cannot get a signal from the hall sensor and I cannot figure out why.

If I cant get the ignition to work I might just cut my losses on the wheel and get a 83 distributor.

 

Any help is greatly appreciated 

post-27559-0-19083200-1418723970_thumb.jpg

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Thanks for the help. My gap is not .040". I read somewhere that the gap had to be smaller then 5mm. I will tighten the gap and run to 12v and see what happens.

 

Now when I made the mounts and installed the wheel, my Efans and intercooler piping were removed but when I put everything back together I found that the fit was very tight. I have also read that the hall sensor is very sensitive to noise. Would my Efan, that is mounted directly in front of the sensor, cause a problem with the hall sensor? 

 

Anyway I took some photos of my setup. 

 

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post-27559-0-26567700-1418785110_thumb.jpg

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Yea has to be closer then that, the info sheet on DIY says up to a 5mm gap, my tuner tested it on a drill press and said he had to get much closer then 5mm to get the sensor to read reliably maybe the total distance includes the valleys? If you shaved the nut that's spacing it a bit you should be able to get closer. Seems like it is angled a bit? See if you can get it more in line with the wheel.

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"Tighter than 5mm"?

 

0.040" is 1mm, and I'm personally surprised it works that far out!

 

If you watch the waveform produced by the sensor, the closer you get the crisper that "chop" gets. That distance is set from the top of the wheel. The "valleys" are out of the sensors reading range (er..."should"...at 5mm...1/4"....it may still read the valleys!)

 

These brackets should be RIGID so no movement. It's not uncommon that chopper wheels on my high speed equipment is set to 0.020" or even closer!

 

I would be somewhere between 0.030" cold, and once warmed up reset it to 0.020" and you should have a nice crisp waveform trigger pulse and can go from there if your bracket isn't a Flex-o-Matic Flexible Flyer Special!

 

FYI a nice roadside emergency fact is common paper is 0.003" thick, so is a soda can.

A Matchbook Cover is around 0.020".

 

Setting with a matchbook on a rigid bracket has worked teats for me!

Edited by Tony D
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Okay so I finally got around to working on the car again. I swapped the 12v wire from vref to a good switched 12v source and the car is now synced. I ran 2 wires for the coil.  coil - to pin 11 on the relay board (I think its labled s5), and I ran Coil + to the fuel pump pin on the relay board with a 15A fuse inline(I didn't have a 10A).

 

Now Megasquirt sees RPM but the car does not start. The coil has no spark. Is there a setting in tunerstudio that i'm missing? I have spark output set to D14. 

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It turns out that my megasquirt was not setup for direct coil control and I am currently modding the board with the bip373 mod kit from diyautotune. The only problem im having is I am not sure which directions to use.. Remember the board is the 3.57.          So the question is, Do I use the 330ohm resistor or not?

 

This: http://www.msextra.com/doc/general/sparkout-v357.html

 

Or This: (http://www.diyautotune.com/tech_articles/using_bosch_bip373s_with_megasquirt.htm)

BIP373s on a MegaSquirt-II V3.0 or V3.57 - Single Coil Hardware mods required:  
  • Jumper IGBTOUT to IGN to send to IGBT ignition coil driver signal out of pin 36 on the DB37. (not needed on a V3.57)
  • Cut out R57 if fitted on a V3.0 (This won't be there on my units, though.).
  • Our assembled V3.57 boards, if not fitted for direct coil control, will have a jumper from JS10 to the center hole of Q16. Remove the jumper from the center hole of Q16, and reroute it from JS10 to IGBTIN.
  • Solder a BIP373 into the Q16 slot, using a mica insulator
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