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Feb 2, 2015 | 08:37 PM

ernie79

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79 400m

Dies when I put in gear I think it could be the modulator valve help please

Feb 2, 2015 | 09:15 PM

HIO Silver

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From: NorCal

And what led to that conclusion?

Outline the steps that have been taken thus far in troubleshooting?

Feb 3, 2015 | 09:11 PM

ernie79

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steps

Set my carb blocked off all leaking vacuum replaced the distributor. Wires New coil and New msd box set timming at 13 advanced. And used water remover in the gas starts grate and will rev to the moon no missing

Feb 3, 2015 | 11:23 PM

tbear853

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From: The Shenandoah Valley

If you suspect a vacuum leak through the modulator valve, unplug the rubber tube leading to it and plug it off and try it. If it still dies, not a vacuum leak there.

I think your problem is carb related.

Feb 4, 2015 | 07:00 PM

ernie79

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It did back fire through it I thought it might b a power valve it is a Holley

Feb 4, 2015 | 09:19 PM

tbear853

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From: The Shenandoah Valley

If it back fired and if it has a Holley that doesn't have either an anti back fire ball check valve or that hasn't been retrofitted with the anti back fire ball check valve in the base plate to main body joint, the violent pressure of a back fire through that vacuum feed port can easily blow a power valve's diaphragm. Only way I know to test it is to remove the power valve and apply vacuum to it and see if it closes against it's spring. A ruptured power valve will cause a rich condition.