Megasquirt II V3 on 87 300ZX Ignition Setup

[300ZXT]

Hello,

I am new here and was in search of some help/pointers. I have a 1st gen 300ZX turbo that I am installing a Megasquirt II ecu with the V3 board (DIY).

Everything in the build has gone pretty well but I am having trouble generating spark. Is anyone running MSII on a 300ZX, even a Z32 that might be able to point me in the right direction? The Z31's came w/ a "power transistor" in addition to the coil. It is supposed to amplify spark/help charge the coil. I have eliminated this from my setup and just have positive to the coil and the neg goes to the Megasquirt and it grounds the wire when it is trying to fire the coil. I tried to put an ohm-meter to the neg. to make sure the MS is grounding the coil, but I think it happens so fast the meter can't react fast enough. According to the nissan manual one can check for resistance in the coil between the two leads (1 ohm) and between lead 1 and the coil discharge (10K ohms). My coil passes both of these tests but could it still be bad? I did the old "pull a spark plug wire" and don't seem to be getting anything.

Perhaps my settings in the MS Ignition setup are not correct (i.e. dwell time and max spark duration).

When I connect the stim to the ecu the ignition led is coming on.

Any help is appreciated.

[evildky]

I responded to your PM and moved this thread to the classic z section

what board version do you have? they all work the same way but the v3 I believe has the driver circuit intigrated

what stim version do you have? the jim stim allows for a lto more involved testing and troubleshooting

what version fo code are you running? you need to be sure that

do you have one fo the case led's set to ign? if so is it blinking when you rotate the distributor?

was the car running before the swap? did you wire up the distributor correctly? it needs power, ground and the 1 60 degree output (the 360 signal wire isn't used) and if you run the Z31 chopper wheel you'll need to run trailing edge trigger iirc (I'm running an L28 wheel)

[SKITTLE]

First off what I would do is to check if you are even getting signal to the coil. The CAS sends the signal to the MS which in turn sends it to the coil and other parts of the system. Take a test light and put it inline with the negatice on the coil (where the MS signal wire should be connected to). If it blinks at a steady rate when turning the key then it is ok and something else is not set right.

Before I swapped to the LT1 I was running MS1 ver 3.57 with #15's of boost.

[evildky]

I appreciate the feedback. The other day while cranking I thought I saw some spark. Then today I saw it again. It is not constant as it should be, it takes me several cranking tries to see something, but I am starting to see some spark. I have asked about this on the megasquirt forums but not much has come back. When you say GM HEI, I would have to re-configure the ms to output on pin 36 by jumpering JS10 to IGN correct?

Just out of curiosity, how many msec of fuel are you injecting on cranking? 10msec?

Thanks in advance.

[evildky]

skittle makes a good point, you must have cranking voltage to the coil, where did you draw the power for the + side fo the coil? it has to maintain voltage when cranking

I still recomend pulling the distributor and turnign it by hand to test for spark

and I was simply telling you I ran the HIE module, I'm nto suggesting that you run 1, if anythign the stock ignitor

and looking at the megamanual for ms2 it looks like you still trigger the coil form pin #36
http://www.megamanual.com/ms2/vb921.htm

and my priming pulse is 1.5 ms after 2 seconds

if oyu pm me your e-mail address I'll send oyu msg of course it won't be correct for your setup but you can see all fo my constants

[300ZXT]

Sorry,

I was away for a day or two and do appreciate all of the feedback. Here are some updates:

I went and exchanged my stock ignition coil (had gone bad some months ago while still running the stock efi).

Yes, the car was running and very well before swapping.

I have a version 3 through-hole board with the 2.88 or 2.89 code.

So, I exchanged the coil (thought I perhaps burned it the very first time I cranked -dwell too high maybe) According to the nissan manual, between pins 1 and 2 should be 1 ohm I had like 1/2 so wanted to make sure.

I set the dwell to 3 and spark output to 2 and it seems like this coil likes that setting. So ok, I see constant spark out of the wire from the coil (before the dizzy). I checked for spark at the # 1 cylinder, and I do see some, but not constant imo. I the engine was out of time (probably is), imo I should still see spark on the # 1 after two crankshaft revs (all cylinders have gone through the cycle). If my engine cranks at 100rpm let's say, 2 secs of the ignition on and I should see it every time.

Anyhow,

What trigger angle do you have? Nissan states 15 deg. +/- 2 base timing. I tried an offset of 0 and 15 in the 600rpm/100KPA bin, and also tried 15 and 15, and have tried other combos w/ no success.

My ignition setpoints are check always for tach sync option, standard coil charge, going high, calculated on the cranking trigger and ignition capture set to falling edge.

I soldered all of my connections, even terminal connections, so I am more confident that I am getting an IGN signal out...I have the stim V2.1 and I see the led lighting up working ok on stim...

Perhaps at this point a timing problem?

[evildky]

to check the timing pull the plug wire form coil 1, and rotate the engine by hand and see t what degree of advance ont he crank pulley the ignition fires for #1, remember when you have to set the ignition back when doign ms so it has lead time, also is it possible that your spark signal is inverted? (or not I can't recall off hand which it should be)

if the coil was bad befre then the car wasn't runing? if the car was running then the coil was fine? and a high dwell will overheat the coil in time but so long as you aren't leaving the key on it should be fine for now

I'll try to emial you my msq form my laptop later tonight