Timing
Postmaster
Joined: Nov 2011
Posts: 2,553
Likes: 10
It could be timing or bad fuel/air caused by carb problems or vacuum leaks. Its best to verify timing first to eliminate it if nothing else. Factory specs vary but most 400's seem to do well with 12 degrees timing advance at idle with vacuum advance disconnected and plugged.
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Senior User
Joined: Nov 2011
Posts: 117
Likes: 0
It could be timing or bad fuel/air caused by carb problems or vacuum leaks. Its best to verify timing first to eliminate it if nothing else. Factory specs vary but most 400's seem to do well with 12 degrees timing advance at idle with vacuum advance disconnected and plugged.
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
It could be any number of things. Without more info it would be difficult to give any kind of accurate advice.
Backfiring can be caused by any number of problems from something as simple as a clogged fuel filter to burned valves.
How long has it been since the truck was tuned up? What kind of shape are the pluq wires in? How does the truck idle?
Check the timing but I suspect the problem is elsewhere.
Backfiring can be caused by any number of problems from something as simple as a clogged fuel filter to burned valves.
How long has it been since the truck was tuned up? What kind of shape are the pluq wires in? How does the truck idle?
Check the timing but I suspect the problem is elsewhere.
Thread Starter
|
Senior User
Joined: Nov 2011
Posts: 117
Likes: 0
It could be any number of things. Without more info it would be difficult to give any kind of accurate advice.
Backfiring can be caused by any number of problems from something as simple as a clogged fuel filter to burned valves.
How long has it been since the truck was tuned up? What kind of shape are the pluq wires in? How does the truck idle?
Check the timing but I suspect the problem is elsewhere.
Backfiring can be caused by any number of problems from something as simple as a clogged fuel filter to burned valves.
How long has it been since the truck was tuned up? What kind of shape are the pluq wires in? How does the truck idle?
Check the timing but I suspect the problem is elsewhere.
Fleet Mechanic
Joined: Jul 2013
Posts: 1,997
Likes: 237
From: NE Ohio
This is a vw page but it doesn't matter as it's the same principle. It can give you some ideas
as to why you're getting a backfire through the carb.
Backfiring
as to why you're getting a backfire through the carb.
Backfiring
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