Where did my spark go??

[jeremiahkellam]

Here we go...

1994 Mustang GT. Engine is bone stock. This weekend started with a MSD cap and rotor, MSD coil, TFI mod is factory orignal, ford racing plug wires, motorcraft plugs

This past weekend at a track event, the car ran great. Then in the 3rd session, it died instantly on track. Back in pits I discovered the tip broke off of the 5 month old MSD rotor. I had a spare BW (Borg Warner) rotor, so I put that in. Ran great for another 4 laps, same thing again.

Then I put my other extra BW rotor plus a new BW cap. This time it took some effort to get then engine started. Once started it idled fine, I rolled the throttle to it, no prob, then blipped the throttle about 50%, it died. It started back up, but the same thing happened again, it died at about 50% throttle. But this time it would not start again.

Decided to pull distributor. Sounded like a fog horn when turned by hand, bearing going out...

New (autozone) dist. Still nothing. Now I'm thinking bad coil

I cut the end off an old plug wire, connected to coil, and got a spark to ground while cranking. Reconnected coil and pulled a plug out, hooked wire up to loose plug, and no spark when cranking. To further test this, I tried other plug wires and other plugs, as well as tried the cut off plug wire i tested the coil with. Still no spark. I decided the new BW cap and rotor might be faulty, put in a used motorcraft cap and rotor, and still nothing.

So, my question is... If I have juice from coil to cap, why is that I'm not getting a spark to the plug wires???

And to answer a questioned asked by a brainiac on Corner Carvers - yes, the rotor is turning...

[Rob Liebbe]

Did you try a different coil yet?

[jeremiahkellam]

No, I thought i still had one extra, but cannot find it.

Is it possible that because the rotor tips were breaking off, the coil could be damaged? Again, I did get a spark from the coil, but how strong, I dont know. Could I still get a spark but it not be strong enough under compression?

[Rob Liebbe]

I don't know if the rotor breaking off would affect the coil.

The spark you see while testing should be a bright blue. Weak spark may not fire.

I'm out of town until Friday. You can borrow my spare coil if you want. Call me and we can arrange for you to come pick it up anytime.

281-413-1948

[Rsmith350]

Have run into this a couple of times with "new" (a.k.a. refurbished) distributors. Put the old one and new one next to each other and get the cam sprockets at the same spot and look to see where the rotor is facing. I've seen "rebuilt" distributors that were turned almost 90 degress from where they should be. :shock: One of my mechanics had me order 4 different ones from different parts people...(autoschmo's, O'really's, Carsquats).......................................O nly one was where it should have been :evil: ......car started up with no problem. Just a suggestion. :wink:

[jeremiahkellam]

Dropped in a new motorcraft coil today and it fired right up.

[GlennCMC70]

add it to your list of spares.

[AllZWay]

Dropped in a new motorcraft coil today and it fired right up.

Good news... at least you got it running again.