Posted May 31, 200222 yr comment_8040 If I let up on the gas, doing 60 or more mph, the car (70z with a 75 l28) backfires. I adjusted the carbs and this reduced, but did not eliminate, the problem. Suggestions? Thanks. Link to comment https://www.classiczcars.com/forums/topic/1801-backfiring-on-decelleration/ Share on other sites More sharing options...
May 31, 200222 yr comment_8046 Do you still have the ABV in place still? (anti-backfire valve) It allows fresh air into the system to prevent the backfires- when i put SU's on my 260, i removed mine, and get minor backfires whenever i decelerate, or use the engine to brake.I try to think of it as the Z "burping" after chewing up some road:cool: Jeremiah Link to comment https://www.classiczcars.com/forums/topic/1801-backfiring-on-decelleration/#findComment-8046 Share on other sites More sharing options...
June 2, 200222 yr Author comment_8170 Yes, there's an ABV.Also, these backfires are powerful, almost as loud as a shotgun. Link to comment https://www.classiczcars.com/forums/topic/1801-backfiring-on-decelleration/#findComment-8170 Share on other sites More sharing options...
June 2, 200222 yr comment_8179 or maybe just one. you said you adjusted the carbs. backfires are from running to rich. lean out the carbs a little and make sure there balanced. also you might want to look into some new plugsjames Link to comment https://www.classiczcars.com/forums/topic/1801-backfiring-on-decelleration/#findComment-8179 Share on other sites More sharing options...
June 2, 200222 yr comment_8195 The timing being off a little could also contribute to the backfiring. If you haven't done it yet, a complete tune-up would be a good place to start. Plugs, points, condensor, timing check, check your plug wires, cap and rotor. If this fails then go for the carb adjustments, and check the ABV. Link to comment https://www.classiczcars.com/forums/topic/1801-backfiring-on-decelleration/#findComment-8195 Share on other sites More sharing options...
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