VB291 do I need them?
 

I'm still trying to peice together all the information I can before I order myself a V3 MS1. The more I read sometimes the more confused I get.

My intention is to run MSnSE, on my 96 VR Limited, I am going to follow the instructions on diyautotune to get spark working, but do i need any VB921's?

As far as i can gather VB921's are ignitors for the coils and my NA coils don't have them fitted, but there's no mention of the in diyautotunes instructions?!?

Soooo do I need them or not, and If i do, are the install instructions in the Megamanual, (I've read it twice, on my third read-through at the moment, slowly sinking in ;-))

Many thanks in advance!

You don't need them. The 1.8 coils have built in ignitors.

cool thanks aussie!

is this the component on 1.8 wheels that are weak and prone to failure if the dwell is set too long?

At a guess I would say that you are probably right. Having the ignitor in the coil will expose it to much greater heat than the 1.6 setup for example and I'd guess that's what is causing the problems.

You could always get some 1.6 coils and run them from the VB921's.

If your going to buy coils. Buy DSM coils.

the what what? sorry i'm in the UK what's a DSM?

Ok I am extending this thread to 1.6 models. I am under the impression that I need the vb921 ignition coil driver for my car. On the board that I bought, the assembler (ebay dealer) performed all the mods that are required to control stock ignition parts on the 1.6. However, I only see one vb921 on the board and I thought that there was one required for each coil ... the miata has two coils though. Am I mistaken or was the assembler?

"Diamond Star Motor vehicles" ... basically this includes Dodge, Chrystler, Mitsubishi are the ones that come to my mind but there may be more. When I think DSM, the Eclipse GST and Eagle talon AWD turbo come to mind first, both with the 2AGE (?) motor. Hope that answers your question.

Check out my install page. The details of how to wire up the MS for spark are there. Compare your board to mine and see if the ebay mods are the same. I have a VB921 ignitor on my MS board too but I'm not using it for the spark.

Everything appears to be all good ... there are a few slight deviations that I have noticed ...

1. D2 was jumped but the diode was left in place (why?)
2. Then there is a connection from R28 -(resistor)-> D12 -> IAC2B (next to F2). I am guessing this has something to do with an IAC ?

It seems like the guy knew what he was doing, so thats good. He said all I would need to get to hook it up w/ squirt and spark was a GM IAT sensor.

Here are his specific Instructions:

"Ok Here are the instructions for the pin-outs for your modified MS for a Miata.

Primary Tach input(CKP)=pin 24
Secondary tach input(CMP)=pin 25
Spark Output A=pin36
Spark Output B=pin31.

Use a GM IAT as your Miata doesn;t have one stock can use GM collant sensor or miata have easytherm value for you if needed.

Use the two wheel decoding in MSNS-E as you have two inputs. If you have any other questions feel free to ask me I will help you as much as I can. Also after recieving your MS if your happy with it and me please leave positive feedback citing Megasquirt.

Thank You,

Robert Turner

Btw, his ebay handle is "shoenf" if anyone is curious

Aye greatly many thanks, I'm going to hold off buying coils unless I blow mine up, (which i'm going to try desparately to not to!

You're good to go.

Start installin'!!!

awesome ... i gotta get a cable sent my way first though as I botched up the one i tried to make. Im also going to order the 200 buck wideband and gm coolant and air temp sensors. Then I should be good to go to tune it up and mess with it on the old dying motor. Then I can concentrate on my motor rebuild.

Anything else you think Ill need?

Lots and lots of connectors.

Tomorrow is the "big day" (The MS will be connected to the car and left there - forever) so I am preparing for ignition. Currently, I'm only doing injection and the ignition is still left to the stock ECU.

My board has 2 VB921s, as it was my intention to use the 1.6 coils without ignitors. However, I have decided to take the risk and use the stock 1.8 coils with the integrated ignitors. So the question is: What do I need to do? Do I remove the VBs and wire the route going to the base of each (removed) VB921 to the respective collector - ie solder pin 1 to pin 2 and leave pin 3 as is?