22 replies to this topic

[steve johnson]

I have a 96 ITA Miata that keeps blowing the coil packs.
I left the car outside overnight a few weeks ago. It rained a bit, but nothing major. Car wouldn't start next day. Thought it was just mad at me for leaving it outside. Figured out the coil pack was bad. Replaced it with a used one I had in the trailer. Car fired right up and thought I had it fixed. Car started for 3 day straight. Let it sit for 2 days, and it won't start again. So, new coil pack, plug wires and I added a power plant frame ground and another ground to the head. Started fine for a few days. Let it sit for 2 days, now the coil is dead again. It has a MegaSquirt. Really want to figure it out before I head to Holy Topeka! next weekend. Any thoughts?

[mdavis]

Battery?

[steve johnson]

Battery seems really strong

[callumhay]

Bad plugs? I can't remember everything that's connected to coilpack circuit but a bad ground or intermittent connection issue in any of the sensors or relays on the circuit. The hard thing with these is finding the most obvious thing without changing everything first.

[Steve Scheifler]

Any idea if they are getting hot, maybe even to the point of melting at spots?

How long since you last made changes/updates to your Megasquirt tune that might impact ignition settings? I don't recall the settings on the NAs which have only the cam pickup, but on the NBs if you configure the crank to trigger on going low rather than going high you can burn up the coils in a hurry.

[davew]

Almost always, when an NA8 has coil pack issues, it is the ground wire at the throttle body. Hard to find but almost always that ground wire is loose, broken or coroded. IIRC it is 2 brown wires

[Johnny D]

 IIRC it is 2 brown wires

 

translation ?

 

Need to add it to the list.

http://mazdaracers.c...nd-greek-bread/

 

J~

[BNaumann]

If I Recall Correctly

[Steve Scheifler]

Almost always, when an NA8 has coil pack issues, it is the ground wire at the throttle body. Hard to find but almost always that ground wire is loose, broken or coroded. IIRC it is 2 brown wires

Good to know!

[steve johnson]

I will check that later tonight. Been a bit crazy here with the moster rains we had last night. Thanks guys

[steve johnson]

Think I found the problem....

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[chris haldeman]

Yea that will do it

[FTodaro]

Another score for Dave. "at-a-Boy"

[steve johnson]

So I hooked up the ground. Attached it to one of the 4 bolts that hold the throttle body to the intake. Put in new coil pack and now it won't even start once. Always before, the new coil packs would run for a day or so before they went bad. What are the chances that I got a bad coil pack? It was a new one from Rock Auto. I'm stumped and throwing $ at this is starting to piss me off

[steve johnson]

Double post
Sorry

[callumhay]

Check u hooked everything up correctly (plug wires in right order, connectors at coil pack) or that u didn't miss to reconnect something. If you are like me, I'm more likely to forget or miss something the 3rd or 4th time I do it because it's not new to me anymore. Failing that , there is maybe something else going on. Check to see if you have spark, if so look at fuel or sensor issues.

[Steve Scheifler]

I've had mostly very good luck with stuff from rock auto, but as it happens I got one bad coil this past spring. The car would start though and run on 3 cylinders. Does yours even pop as if one side might be working?

[chris haldeman]

Swap the connections on the coil pack.

[steve johnson]

Got it up and running. Turns out, the new NGK plug wires didn't go far enough into the holes to actually clip on the plugs. The rubber boot was snug, but the metal clip wasn't getting on the end of plug. Guess that's why you should only change one thing at a time when trouble shooting. Thanks for the help guys.

[davew]

That is the reason I do not use NGK plug wires, poor fit and they fall off. I use MSD wires on all my cars. uess where you can buy them ????