Weird backfiring - Team Camaro Tech
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post #1 of 9 (permalink) Old Jul 8th, 01, 01:35 PM Thread Starter
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I just came off of my first real long drive with my car. (69, 327, m21)

I went approx. 30 miles on the highway at around 75mph. I know, that's peanuts compared to some of you guys, but it was my first real "long haul" in my new car.

Anyways, now when I'm down in first or second gear, I'm getting little backfires periodically. They're not a nuisance, but they're a "new" noise that I didn't have before.

Any ideas, as to what they might be??
All info is greatly appreciated!

THNX!

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post #2 of 9 (permalink) Old Jul 8th, 01, 02:42 PM
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If it's kinda a "sneeze" when you are really out of the throttle, you may be too lean on cruse mixture or have some pluggin of the carb air bleeds, maybe a float level that is too low.

If it were under power, I'd suspect timing that is retarded.
David

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post #3 of 9 (permalink) Old Jul 9th, 01, 08:36 AM
 
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This could be a possible timing problem. Make sure none of your spark plug wires are arching on your headers if you have em. I have notices any type of miss in these cars can possily create a backfire
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post #4 of 9 (permalink) Old Jul 9th, 01, 10:05 AM Thread Starter
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Thanks alot guys! I'll look into it.

John
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post #5 of 9 (permalink) Old Jul 9th, 01, 12:20 PM
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I second js67ss350's comment. I just had the very problem you have described. It appeared suddenly and it was somewhat intermitent. Eventually I caved in and replaced all the plugs. What I found was that it wasn't the plugs, but the number 5 header cooked my MSD plug boot enough to allow arcing at certain RPMs. I replaced the boot and changed the orientation, problem solved.

The lean condition comment is valid, but since this suddenly appeared, the boots/wires are worth taking a look at.



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post #6 of 9 (permalink) Old Jul 9th, 01, 07:03 PM
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If it's an exhaust pop, look for an exhaust leak.
Is it a carb backfire?
David

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David's Motorsports page
First Gen Suspension Page
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Chev 350 Can-Am Vintage Racer
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post #7 of 9 (permalink) Old Jul 10th, 01, 05:43 AM
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If the engine is older...I had a 327 that the one of the cam lobes went bad and caused backfiring throught the carb when I let off the throttle. I pulled the cam and one of the lobes was history. Other than that...timing maybe the problem or fuel mixture.
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post #8 of 9 (permalink) Old Jul 11th, 01, 09:31 AM
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Most likely, the dwell is off. Make sure your points & condenser are good, then reset the dwell & timing. I had a very similar problem and this took care of it.



[This message has been edited by RW68RSConv (edited 07-11-2001).]
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post #9 of 9 (permalink) Old Jul 12th, 01, 06:03 AM
 
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Change your spark plugs!
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