At a loss - engine stalls under load

[R68GTO]

I agree Maroman.....does anyone have any tips on where to look next?  Could this be a problem under the dash?  In the steering column harness?  What likely suspects would cause the power to the coil to be interrupted under load?  What I do know is that with a brand new wire, the same symptoms exist, so it likely is not the wire.

[Chuck-68-Cam]

I agree with someone who said earlier...It sounds fuel related? I see where it said you changed out the fuel pump, did you replace filters. It just sounds like not enough fuel when you punch it under load.

[R68GTO]

Multiple times on the dyno when it stalled, we check the float bowls on the carb.  Each time the fuel level was at the bottom of the sight screw.

[rich69rs]

What electrically is “in the circuit” now that wasn’t when you used the MSD distributor & box?

If the car truly ran correctly on the chassis dyno with your ignition system not used/bypassed then methinks you have isolated the problem.

Richard

[David K]

If possible, I would have a voltmeter connected to the coil to see if it stays put during the power loss.

[R68GTO]

When the problem disappeared, we were running an MSD distributor and ignition box wired directly to the battery.  In prior attempts to solve, I had replaced both the distributor and coil with no change in symptoms.  That leaves the wiring from the positive side of the coil back to the ignition switch on the column.  Wire from firewall block to coil just replaced, so that leaves the stuff from the fuse box back to the column switch, and I guess the power from the battery to the column switch.  What could go wrong in those areas that only shows up with the engine under load?

[Tinkerr]

Was the replacement  Distributor points and condenser unit? If so you could use a ballast resistor run 12 volts direct to bypass the factory wiring for testing purposes. If that corrects your issue as it did with the MSD you know the issue is the car wiring.

[R68GTO]

Tinkerr....to bypass the car wiring would you run a wire from the battery to the positive side of the coil with a ballast resistor in line to reduce voltage to 9.6V?  Would I then also have to run a jumper to the starter wire?