Backfire: What are the main causes
Post Fiend
Joined: Jan 2000
Posts: 5,860
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From: Metro Detroit (Redford)
Backfire: What are the main causes
I recall a backfiring truck at the auto shop I go to. Turned out the guy had put a new set of plug wires on and got a couple of them crossed up. I assume one was firing near the end of the exhaust stroke when all the fresh fuel air mix was being pushed down the exhaust pipe. A wonder it didn't rip his muffler open.
Freshman User
Joined: Nov 2000
Posts: 29
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Backfire: What are the main causes
When does it backfire/
All the time or under power
It could be a number of thing (i.e.) plug wires, valves sticking, timing chain slack,
But when you do find the problem be sure to replace the power valve in the carb, when you back fire into the carb there is a tendancy to blow these out.
Let me know.L8TR
All the time or under power
It could be a number of thing (i.e.) plug wires, valves sticking, timing chain slack,
But when you do find the problem be sure to replace the power valve in the carb, when you back fire into the carb there is a tendancy to blow these out.
Let me know.L8TR
New User
Joined: Dec 2000
Posts: 23
Likes: 0
Backfire: What are the main causes
If it's old enough to need new plug wires, or you don't personally know how old they are , change em with good ones -(lifetimers - or something like that. Myterious misses, backfires, etc under loads seem to show up more with older wires -that way you isolate the problem more and it's good insurance for the future. Sometimes by running it in the dark you can get a glimpse of some sparks around the plug wires when you rev it.
