stevenford_uk

since i have fitted the coil on plug setup a misfire has developed, and the tach dies everytime it happens, i am thinking there must be a way of stopping this but unfortunatly i dont know how, so i am again turning the the wealth of knowledge on here.
any ideas please guys
thanks in advance

Matt Cramer

Does the Miata's tach die, or do you lose the tach reading on the Megasquirt?

stevenford_uk

miata's dies and the megasquirt spikes, but then both return fine and then it happens again.
all very intermittant

Matt Cramer

Could you see if you can catch the tach spikes on a data log? That might give me a bit more of an idea what to look for.

stevenford_uk

got them on there, i just dont know how to post a file on here

richyvrlimited

iTrader: (1)

zip it up and then use the attach file option when you post

stevenford_uk

awesome mate, thanks

arga

I am really sorry about hijacking another one of your threads but I can't let this go. What are you using for coils on your COP set up?

stevenford_uk

coils off a yamaha r1
using the std mx5 1.6 ignitor

mschlang

What kind of timeframe are we talking about? I have a similar problem, random drops of the stock tach and an engine miss. The tach drop for me is a sudden thing, most passengers don't even notice unless I'm on it.

In the attached log, the spike/drops are right before the marks. I have a thread on this at msextra.com, http://www.msextra.com/viewtopic.php?t=23938&highlight=.

stevenford_uk

less than a second mate, its all very quick but very noticable.

mschlang

Same thing here, just a blip on my highly calibrated butt-dyno.
Could you outline your ignition input and output wiring, maybe we can get this figured out.

My trigger input mods are:

Q6 and Q8 removed
C12 and C30 removed
D1 removed and replaced with a jumper
Backside mods from http://www.diyautotune.com/images/ca...input-mods.jpg

Output mods are:r26 top to IAC2a and r29 to IAC1b

cjernigan

iTrader: (13)

DIYautotune recommends leaving Q6 and Q8 in when using their spark mods. Are you currently running without them?

stevenford_uk

not sure, i cant remember, ill rip it out today and check it.

stevenford_uk

ah not directed to me but helpful to know still. lol

mschlang

Yes I am. I haven't the time right now, but I need to figure out the difference between the spark mods in "kags" "My MS install" sticky and the directions on DIY. My mods are from the sticky, where Q6 & Q8 are removed.

mazdasly75

Hi guys,

when running wasted spark or COP, it is recommend to install a 25uf capacitor. One lead goes to the 12v source that feed the coil, and the other lead goes to a ground, in this case you ground it somewhere on the head. You want to connect the 12v source, closest as possible to the coil.

OEM's coilpack carry those capacitor

stevenford_uk

here is the datalog guys, sorry its taken ages to put it on here, had loads of work to sort out.
please let me know what you think

stevenford_uk

thanks for the heads up about the capacitor, but i have put the ign back to std now and its still doing it, mainly under load tho.
anyone had chance to check out the datalog?

Matt Cramer

I see you have noise in the tach input signal - sometimes pretty serious noise. Check your grounding thoroughly, and if that doesn't help, you might want to do something to shield the CAS wires a bit more thoroughly. It may be the coils you're running create more electrical noise.