Ignition trouble ...

[Noob]

Okay, my cobra is built, and I had actually put about 200 miles worth of shakedown on it.

Last week I was driving it, fortunately close to home, when it suddenly shut down.

As of now, the car will fire, run for about 2 seconds, and die.

I placed a test light on the coil, and it will not light when the key is in the "on" position -- only during the start and the second or two duration following before the engine dies.

I replaced the ignition switch (cylinder) with a new 4-position one, but that apparently isn't the problem, the car still behaves the same.

Where do I go from here?

[nolastyankee]

Do you have an ignition box? If yes the below may not apply...

If memory serves, in the regular wiring harness the coil receives power from the starter solenoid during start, but depends on a different wire to power during run. (This is to isolate power to the engine during start)

The source of 'run power' is the fuse box or the ignition switch. Check to see if you have power coming into the coil (not the coil itself) during run. Going way out on a limb here, but I think the 'run power' for the coil is via a gray wire. If you don't have power at the terminals of this wire in run, check the other end of this wire behind the dash, then keep working upstream until you find the fault. Could easily be a broken wire at a terminal.

Funny coincidence with this problem...We killed our ignition box last week and are back on jack stands for the time being.

[Slither]

Sorry to hear that Brian:(. How did you manage to do it:confused:?

[nolastyankee]

Sorry to hear that Brian:(. How did you manage to do it:confused:?

To be honest, I have no idea how we killed our ignition box. It's off to Accel right now for a warranty repair. We had driven the car and it was out in front of the house idling and just died. After that, no power to the coil from the box. The signal from the DFI system was present, but nothing in between.

As long as the part warranties it's no big deal...Just part of the sorting out process!

[Slither]

Gremlins:eek:! Good luck, and let us know how it turns out.

[weaver]

Noob, do you have a Unique?

Alan

[Noob]

Yep, 289 FIA. No ignition box as well, to clear up the earlier post.

I've been piddling around with it, but it'll prob have to wait a day or two until I have time to get the dash off and really get into chasing wires.

[Jim Harding]

Noob, two things come to mind. 1, a broken wire between the run terminal of the ignition switch and the coil, and 2, a burned out ballast resistor if your car is so equipped. Finding the broken wire calls for a 'hand over hand' following the wire from point A to B. The ballast can be checked with your test light... with the ignition switch in run, check each terminal on the resistor. If only one terminal lights the light, the thing is bad. You might also check the wire from the coil to your tach, it may have come loose and shorted to ground.

[weaver]

Try running a new wire direct from the IGN post on the switch to the positive side of the coil, run it over the windshield frame just to see if that is the problem. Try pulling the original wire at the connectors to see if it has a loose connection before disconnecting the old wires. Did you send our punch back, we will need it soon.

Alan

[Noob]

Alan, just got off the phone with John's son who's staying at their home. I knew I'd mailed the punch--but its back at their house, returned for postage. Its just been sitting there. I'll head there at lunch and get it back to the post office. BTW, all went smoothly with that....thanks again!

Will be working with the car tomorrow afternoon, and promise to check back in with the results! Thanks for the ideas!

--David

[Noob]

Well, its not pretty. A complete section of the wiring harness appears to be toast. It seems the damage was done by the white wire (#36) running to the (+) of the coil...


http://i42.photobucket.com/albums/e308/paresthesia32/Toastedwires010.jpg?t=1189725456


http://i42.photobucket.com/albums/e308/paresthesia32/Toastedwires008.jpg?t=1189725560


http://i42.photobucket.com/albums/e308/paresthesia32/Toastedwires012.jpg?t=1189725630

[Naumoff]

That might be the problem.;)

[weaver]

If you don't use a MSD box you will have to run a balast resistor, that is where the white wire would go.

Alan