mschlang

Spurred on by my findings here, I did some digging tonight. By hooking up a timing light to each plug lead, I found out that I need new coils. The left terminal on each coil is miss-firing, shown by the drop out in the strobe light. The right terminals show a nice even flashing. The engine rpm also slows a bit right after the strobe drop out.

If I am going to replace the the coils, I'd like to upgrade while I'm at it. I'm looking for something that goes in with minimal fabrication and will stand up to more abuse.

92MX5

iTrader: (1)

Moss Motors has this for $289: click.

You could also do the DIY coil-on-plug setup that others have done and documented on this site.

Cheers!

Jeff

lazzer408

iTrader: (1)

I'd hardly judge a missfire with a timing light. Are you running rough? On wasted spark coils, one terminal is neg and the other positive (of the secondary winding) and the current flows thru one plug, thru the block, then back up the other plug. It fires 2 plugs at the same time. 1&4 and 2&3. Read my COP thread and give those a try. It's cheap, plugs last longer, run cooler, and no wires to fail or replace. win win win

mschlang

I'm not sure why not. The light flashes smoothly on two of the terminals, and has intermitant drops on the other two. It is reapeatable after swapping wires on the terminals (It doesn't follow the wire). Add that to my experience in the previously linked thread, and my observations from driving the car w/ MS for the last year. There is little question that the coils are at fault.

If I can find them at the pick n' pull, I'll give them a shot. It is an attractive solution.

Anyone have experience running the neon or DSM coils?

iWeasel410

I have an extra Neon/4g63 coil as well as an extra 1.6l coil, PM me if interested.

mschlang

Alright, problem solved. I did two things. First, a 6 gauge ground wire from the battery to the block. Second, a "new" coil from a Hyundai (or Kia, I don't remember). I don't know what did it, but the misfire is gone.

lazzer408

iTrader: (1)

Some timing lights have issues at higher rpm. They "mistrigger" for lack of a better term. Some of them have directional pickups to help prevent this but that can cause issues with wasted spark ignition if you don't know the current path of the the plug wire your clamped to. The lable "to plug" on the pickup wouldn't necessarily be correct.

Anyways...

Glad to hear it's up and running.