351 Backfires During Warm up

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Jan 19, 2003 | 08:23 PM

Kodiak_Dan

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From: Kodiak, Alaska

351 Backfires During Warm up

My 1985 F-250 with a 351 starts right up but begins to backfire badly out the exhaust until it has reached operating temperature. The problem is made worse when the weather is wet. I suspect raw gas is being dumped somewhere but what would cause this? The distributor cap, rotor, wires, and timing are all good. Any help much appreciated!

Jan 21, 2003 | 09:18 PM

1984_355w

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From: Illinois

351 Backfires During Warm up

Backfiring is usually a lean condidtion and that's why it happens when it's cold outside. Take a look at the plugs. Do you have glasspacks? If so, my '84 used to do it too. after the flows went on all of it went away.

Jan 22, 2003 | 10:40 PM

fastf150

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351 Backfires During Warm up

Check the exhaust for any leaks you may have where it is sucking in exhaust somewhere. Also, if it is carb. check your choke make sure it working right.