[DML] Still -more- ignition nonsense....

["cruznmd" <racuti1@xxxxxxxxxxxx>]

Lately I have been testing my timing advance as a theory regarding my 
power fall-off when you apply more than 1/2 throttle too quickly. I 
thought perhaps the centrifugal advance was sticking.

I have verified with a borrowed gauge that the vacuum advance is 
correct, and with an advancable timing light, that the centrifugal 
advance is correct. The advance apparatus doesn't stick or hang at 
all.

Here's something new that I've discovered that I'm at a total loss to 
explain:

When revving the engine (in the driveway) slowly to check all of the 
different advance points, everything is fine. If you "spike" the 
throttle (putting a load on the engine similar to the load from 
actually moving the car), the timing light goes out. This is a BRAND-
NEW, quality light. It does this on ALL spark plug wires. When the 
engine is under load, and the light goes out, the engine sputters. 
After struggling mightily, and the engine spins up a bit, the timing 
light comes back on, but it's dim and erratic if I keep the load on.

This is with an 18Kv Bosch coil from John Hervey, or a 25 Kv Accel 
coil. If I put my 23 year old blue coil in, or the new, cheapy 
generic 12kv coil that I happened to have laying around, the light 
gets dim, and erratic but it won't quit firing no matter how hard I 
spike the throttle, and as with the hotter coils, once engine speed 
spins up it becomes better, but better than the hotter coils.

So I put it to you:

Why do I experience a near-total loss of spark under load? Especially 
with a higher voltage coil? (I know some of you are running MSD's and 
Pertronix coils @ 40Kv so I don't buy the "your coil's too high a 
voltage" theory. It sounds like something is breaking down under the 
higher voltage.

Remember: I've replaced ECU, wires, cap, rotor, coil, ballast 
resistor, checked advance, pulse coil resistance, coil input voltage, 
resistance of several coils, re-terminated wires, applied di-electric 
grease, -and- checked all of my fuel pressures with a Bosch K-jet 
test rig.

Thanks for all the help. Keep it coming.

Rich A.
#5335




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