Backfire problems

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Aug 30, 2006 | 05:45 PM

deadlylama

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Backfire problems

I have an F-150 with a 400 in it. And Whenever I step on it it backfires. And I was wondering why this happens, and how to fix it. Thanks

Aug 31, 2006 | 04:51 AM

Torque1st

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Hello, welcome to FTE!

Hesitation or flat spot can be either carb or timing. Make sure your distributor mechanical and vacuum advance is working properly. Make sure the carb accelerator pump is working.

There are threads here on how to test both of these systems. The carb forum has more carb info.

Unfortunately backfiring can destroy the power valve on the stock carb. The carb forum will have info on testing and replacement.

Aug 31, 2006 | 06:29 AM

Sycostang67

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From: Kuna ID

Have you messed with your plug wires lately? I did a tune-up on a 460 once and it started backfiring when I gave it gas, it turned out I had swapped 2 plug wires.

Aug 31, 2006 | 11:07 AM

Mil1ion

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Does it backfire out the carb or out the tailpipe ?

Aug 31, 2006 | 04:54 PM

deadlylama

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It backfires out of the carb.

Last edited by deadlylama; Aug 31, 2006 at 05:06 PM.

Aug 31, 2006 | 06:02 PM

Mil1ion

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Check the distributor shaft for play sideways.

High mile parts like distributors show up re: problems different ways.

Back-firing out the carb can be ignition or fuel related.