the ignitor fires the coils...

 

My understanding is

ECU gives power to the ignitor module, from ignitor module, it goes to a harness and then the harness connects into the coil pack harness which is the plug that is to the left of the item I'm pointing to

As noted, I've already swapped in another ignitor module and CAS with no difference.



If worse comes to worse, one of the shops said they'd troubleshoot the car, about 1-2 hours of time at $120/hr. But I'm not giving up yet, I think it has to do with no spark.

 

can you verify your cams are actually spinning when you crank?

just pop the oil filler and look.


also, remove both add a fuse, fuses and see if that has an effect. the way the MS was acting says you have an electrical issue. form where, dunno.

 

I'll check this out when I get home. Going to have to somehow rig up something to check into through to filler hole while I'm in the car

 

Something could have come loose but appear to be connected. Something might also have previously been a bad/intermittent connection and have now vibrated into being connected most of the time. Bad grounds can do really odd things.

It's also possible that the seller lied to you about the state it was in when it worked because he knew you wouldn't buy it otherwise...

Pull the radio out and see where those power wires go?

If it were my car, I'd rip out every single wire that isn't factory, check out any factory ones that look like they might have been molested with a DVM and/or scope, compare to the factory wiring diagram to look for stuff that might have been rerouted, and only then worry about the coil/etc. That way you have a known base point to go from.

--Ian

 

too much logic in this post.

its much more efficient to waste weeks upon weeks upon weeks hacking together a molested rats nest of wires and just guessing

 

First of all I'd like to thank Cordus for taking his time to come over and check out the Miata last night. Sadly, it looks as though all of the hardware checks out and I'm going to have to start digging into the electrical.

Oh JOY! not lol

Don't quite know where to start but I think I'm going to start at the igniter module. This is a pretty good diagram to start me at

http://www.miata.net/garage/ECU%20Pi...90-93%20MT.pdf

 

that's an awful diagram to start with.


use this:

http://www.miataforumz.com/1990-200-...ing/92diag.pdf



why start at the ignitor??? start with the AFTERMARKET, **** JOB, RATS NEST, WHAT-BROKE-THE-CAR WIRING!

 

So I spent some time on the car testing things out and I can conclude that the car isn't getting spark and I have no idea why.

I used an inline tester on my NA and no light, I do the same exact method on my NB and I get light

IMG_20130808_195928_zpsde05f940.jpg?t=1376017203

Things I've already changed out/tested

Hardware
1. Ignitor module has been swapped with a spare ignitor module
2. Coil pack has been swapped with a spare coil pack
3. CAS has been swapped with a spare CAS

Wiring
1. Continuity tested from the ignitor module to the coil pack plug
2. Wtih car in On position, 12V reading at coil pack plug for all 3 pins

 

So I saw this video


And I tried to replicate it. I pulled my CAS, pulled the spark plugs and connected them to my spark plug wires.

How is he getting spark if the plugs aren't grounded to anything? Also, is the wiring between the plugs necessary?

If I can get spark doing this, the I don't know what's going on

 

Don't you see the wires wrapped around the threads of the plugs? They are going to ground.

 

They just go from the threads of one plug to the threads of another (at least, per the audio track on the video). That doesn't ground them.

--Ian

 

i didn't listen, I just watched and saw wires and assumed they went to ground, which would seem reasonable. Couldn't really tell on the vid.

 

If they do, the last one is grounded somewhere. I've done this before to check for spark, although I use four different ground wires. I suppose you could just as easily daisy chain them together only grounding one, they're all ground in the same head.

 

Did you ever confirm or deny that the ECUs are toasted, from all the cranking done without the ground strap wire in place?

 

How would I test out if the ECUs are toasted?

 

Buy another Miata and swap 'em!

C

 

First, I would probably take it apart (Megasquirt), and look for any sort of obvious issues or damage. Then from there, try to connect to it with a computer and make sure everything appears to be in order, functioning properly, etc. IIRC you were able to connect to it once, but have not been able to since? Perhaps that's a sign it's not working right anymore?

 

Im assuming he grounded them in sequence through one another. the last wire probably goes to ground as stated above.
Think about your plugs, if you look at them, every other one (prong/electrode) is usually worn out opposite (assuming they have some mileage on them) the first may have a worn prong, the next will have a worn electrode, the next will have a worn prong, the next will be the electrode. They Tend to ground through one another, to one common ground.
Basically what this guy was doing WITHOUT the head.

BUT......... you have no spark..... so thats neither here nor there...... lol

 

Tere's no evidence of it in either the audio or video tracks. OTOH if he wired it up the way he described it in the audio track, then it shouldn't fire, so I have no idea. It's not really relevant.

HH's megasquirt shows no obvious physical signs of being fried. No scorch marks on the board, no "magic smoke" smell. OTOH, it does really bizarre things when powered up, even when it's supposed to be doing nothing (key off).

--Ian