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supernova_6969

280zx ignition module with Megasquirt - is it necessary?

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hi guys.

 

I'm still trying to find why my car runs like crap, after 3 years (although I'm doing less and less about it.  project fatigue combined with lack-of-a-clue-paralysis).  Part of the problem is that I bought someone else's project (complete) "that only needed to be taken to the dyno for a tune," and since I didn't build it myself, I'm not sure what could be wrong in the set up.

 

Issues i'm having is that it runs rough, both at idle and when driving.  It'll misfire pretty much all the time, espcially under boost (but not ALWAYS).  It's got a megasquirt, but it's essentially untuneable;  I'll work on getting some ok AF mixtures, only for the AF ratios to go crazy for a week or two, then to change again...  there are a few other weird things, but..  that's not the point of today's topic.... 

 

I've been thinking that my stock, original coil might be a little old, maybe not producing enough voltage anymore, or skipping some ignition events...  but there is also the ignition module between the Megasquirt and the coil; that could also be faulty, 

 

I've seen set ups where the MS2 runs the coil directly... (DIYautotune https://www.diyautotune.com/support/tech/install/nissan-datsun/megasquirt-your-280zx-turbo/)...

 

so really, I know I could modify my MSII to run the coil directly, is there a benefit to having a ignition module?  should I even be looking at it? 

 

Thanks.

 

Seb

 

Edited by supernova_6969

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I'm a few weeks away from installing my Megasquirt setup finally. I don't plan to use the ignition module. It's just a basic transistor to amplify the signal and that's exactly what the MS board had if you have the stated ignition output stated in the diyautotune article (which means most units built unless it's ms1 or you build it yourself).

 

Have you done in depth ground testing and experiments? My first guess if your AFRs are sliding around would be sensor noise.

 

Get some log exports and share them. Maybe someone can dig in and see if there's a lead up to missed ignition events.

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I would use the BIP 373 drivers in the MS. Switch to a crank fire trigger wheel or install the 82-83 280ZX Turbo distributor with Optical CAS trigger. With the  Turbo CAS distributor you will have to purchase the DIY Custom trigger wheel for the L27ET engine. The advantage of using a Crank Wheel or CAS distributor is that now you will have fully programmable ignition timing. 

 

With three BIP373 coil drivers you can run Waste-spark spark ( 3 x twin tower coil packs.) and Batcfh fire injection on an MS2

 

If you add in an MS3X expansion daughter board, you can have full sequential fuel injection and 6 individual COP ignition coils on an MS2. 

 

Look on our Vendors forum. Softopz is a MS distributor and he can either build you a new ECU  or repair/update the ECU you have. He also makes excellent Plug and Play custom harnesses.

 

http://forums.hybridz.org/topic/128308-megasquirt-plug-and-play-harness-and-pre-configured-ecus/

 

It may be a good idea to send the MS2 ECU to him and check it for any hardware issues. MS units can be built many different ways. And the build quality of course depends on the skill of the builder. used units can be a crap shoot.

 

If you need Tuning, I can help you with that. I Remote Tune MS1, MS2 and MS3 ECU's. primarily for the Datsun L-serie's.  You can PM me for more info.

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Gollum:

I'll make sure I check my board;  the board I have is a DIYautotune board, pre-built kit.   if anything, I'll see if I can get rid of the module;  any one less potential faulty part is best!

as for the ground testing, I haven't.  I did add a ground to the CAS cable's shielding, but it didn't change anything (it wasn't grounded, but I should check to see if I did it properly). I was thinking of re-making a whole new look, as the one I have is too short in some places, and it makes for an ugly, messy engine bay..  doing that would also enable me to make certain everything is well plugged, soldered, crimped and grounded.  

as for the logs, I did post some topics on the msextra sites, with some logs, and some of the big names there looked at it, but nothing came out of it (although not that many people did look at ithem)

 

Chikenman

Thankks for the ressource.  where in canada are you?  

I already have the 83 turbo distributor.  the car also was dyno tuned at some point (before more extensive mods were made to the engine) so I expect the components, including the ecu,  to be good..  testing the quality of the signal with an oscilloscope is one of my eventual projects..  I'm just not inclined to start because I know very little and just lack confidence.

 

thanks for wtriting guys. some (most) of the stuff both of you said is real interesting...

 

Although, back to my original, question, are there advantages or disadvantages to using a ignition module?  other than added parts?

 

Edited by supernova_6969

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Do you know how to create a log file?

 

Start it and runit for a while and then send it to me. Also include the tune.

I can see if I have the time to take a look.

 

I am doing fuel only with my (non turbo) setup. It's the first step, once that is working you do timing.

 

Are you sure your MS is driving the timing?

 

I will do what Chickenman suggested as well, but I will probably buy the Quad Spark module and maybe the IGN-6.

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18 hours ago, supernova_6969 said:

I did add a ground to the CAS cable's shielding, but it didn't change anything (it wasn't grounded, but I should check to see if I did it properly)

 

Shielding should only be grounded inside the ECU. The other end should never be grounded to anything.... 

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Advantages to running an external  Ignition Module:

 

1: Ignition modules are noisy electrically ( EMI ) . For that reason, some builders of MS prefer to keep the high current  Ignition coil drivers ( BIP373  IGT) outside of the ECU box. Or they build a Faraday cage around the Power Transistors. An external Module, be it a Nissan Matchbox module, aftermarket Ignition amplifier, such as a Bosch or DIY Quadspark unit or even a CDI box, will be isolated outside of the ECU as far as EMI noise is related. Very few manufacturers such as Haltech, Link Adaptronics, or AEM, ever include the High Amperage draw IGT drivers isiden the ECU. They all use external modules to reduce EMI. 

 

Logic coil drivers are not the same thing. They are low amperage circuits and don't produce the EMI that the IGT BIP-373 coil drivers 

 

Advantages of BIP 373 drivers ( IGT ) 

 

2: The BIP373 drivers are cheap ( $8.50 each ) work well and provide a slightly cleaner install over external modules. We are referring to dumb coil packs of course. Logic  coils such as LS2 do not require IGT coil drivers. 

 

 Cons of external Modules. 

1: More cost if one has to be purchased. Can be quite expensive if going more than a single coil. You need at least a 3 Channel coil Module for a 3 Coil Pack Wastespark system. That can be fairly expensive. Although you can sometimes find used 3 Channel Bosch modules for a reasonable price. . Audi V6 and BMW inlne 6's prior to about 2000 had these. 

 

2: Additional wiring. The Nissan matchbox module would have to be re-wired to use the Programmable Timing curve features of the MS. And the distributor would have to be locked out. Not really a Module issue, but rather a choice of distributor type. 

 

Cons of Internal coil drivers. IE ( BIP-373  IGT coil drivers )

 

1: They produce an ENI field. Nota good thing to have inside an ECU with very sensitive micro-orocessors.

 

2: They get hot. The more of the BIP-373 drivers you have, the more heat is pumped into the ECU case. Heat is not good for electronics. Worst case scenario for an L-6 would probably be three BIP-373's firing 3 x Waste-Spark " dumb " coil packs. 

 

 

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hey chickenman.  

 

for the CAS shield, I grounded it straight to the engine block, at the same ground location as the engine.  next time I'm in there, i'll ground it to pin 2 on the MSII connector...  I'll also make certain I actually make a good connection to the shield; that's what I did...  rather quickly..

 

And thanks for the answer about advantages and disadvantage.  it's super complete and very clear..    Just quickly, is there a reason why the BIP-373 (which seem to me like they are mosfetts) couldn't be housed outside the MS box, like in the relay box, if you have one?  Could that be used as a home made ignition module, driven by the MS, allowing the battery 12v (or ground, is it?) to go to the coil (or something)?  this is a purely theoretical question.... 

 

as a side note, I have the modern turbo dizzy with optical CAS and ECU controlled advance, so the module does not have to be reprogrammed..  yay that!

 

Thanks guys!

 

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With the ground shield it must not be connected to the engine block or Chassis. Only to the inside ECU ground. Having grounds at both ends can induce an offset voltage into the ECU sensor ground circuit. You don't want that. Messes up sensors. 

 

I've heard of MS custom builders using a separate box outside of the main MS ECU box for exactly the reasons stated above.  To reduce any internal EMI created by the Power transistor  ( BIP-373 ). Very good idea with WasteSpark or COP coil drivers that would have multiple BIP373's. 

 

The Nissan Module could certainly be triggered and controlled as a Single channel dumb coil driver. That's exactly what it is. Be sure to mount it to a good heat sink though. Those modules get very hot. The distributor body acts as a heat sink from the factory. If not mounted to a heat sink it will fail in short order.  The Nissna " Matchbox " module is pretty stout all by itself. 

 

You can use an old AMD style CPU Heatsink and fan to keep it cool. Fan may not even be needed. Make sure you use a good thermal conducting compound between the Module backing plate and the Heatsink. 

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You never mentioned the distributor your running maybe I missed. 

 

Concerning the ground factory zxt diZZY BLACK connect at end of plug to shield so it's all the same. And diZZY IS GROUNDED TO ENGINE. Ms2 pin 2 is shield however If you look at schematic of ms2 circuit board they all ground to same plane. Pins 1 2  7 15-19 so ye lots of debate on grounds. Even the black white sensor ground! The important part is it grounded and shielded. https://www.diyautotune.com/support/tech/other/grounds/

 

Also you linked the DIY article and you had the board setup for but not using the high current driver? Which IGN module are you running and what's your ms ignition settings?

 

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hi!

 

softopz..

 

I've got a stock ZXT dizzy, with the (i believe) stock wire going all the way to the MS2, where the end was cut open and the wires spliced in to the connector, (and a resistor, somewhere if I remember correctly).    The shield, on the ECU side, was simply there, but not grounded, si I ran a wire from that to the engine, simply twisted.  in the next few weeks, I'll actually solder this and ground it to the MS2 instead of all the way back to the engine.  

 

The link I posted, I realized after, seems to be for direct coil driving, while in my case, the ECU sends a signal to the stock ignition module, which then drives the coil.   Since this is how it's set up, I suspect that my MS2 is not setup for direct drive, but I'll try to see that when I solder the ground properly;  while i'm at it, i'll open the board and sneak a peak at it to try to see what I can find there.  I used to have a photo, but can't find it anymore..    I might take a new one and post it back here...

 

as for the ign setting,s i'll try to grab the info at the same time and post back.. 

 

one thing you mention, about the grounds, is kindof what I've been thinking about;  all the ground pins are essentially the same, just many ports to the same ground, which means that, theoretically, I could ground anything that needs grounding (like the O2 sensor, the timing signal shield, and tps sensor) in any of the ground pins?   and what's a black white sensor? do you mean the ground for the ign. timing sensor?

 

thanks for taking the time.  

 

seb

 

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I meant black white according to ms2 diagram is the sensor ground for TPS, CLT, and iat. 

 

Regardless if they a.connect internally all ms ground must be connect to a good engine ground and in one lug.  Take a pic of your ecu and attach.

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