305 backfire through carb
#1
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Car: 87 sport coupe
Engine: 305
Transmission: 700R4
Axle/Gears: 2.73
305 backfire through carb
I have an 86 camaro z28 with 305 motor that everytime i try to drive it down the road repeadly backfires through carb. When idling in neutral runs fine no backfire. I have replaced distributor cap, rotor, spark plugs, wires and i am at a loss. Any help would be great. Thanks
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: 305 backfire through carb
Prolly not the timing. Basically that problem never is.
More likely, not enough fuel.
Changed the fuel filter?
More likely, not enough fuel.
Changed the fuel filter?
#4
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Car: 85 z28
Engine: 355ci
Transmission: th400
Axle/Gears: 3.73
Re: 305 backfire through carb
also..did you go with exact same plugs for replacement? the 305 doesn't like a hotter plug than came factory is why i ask. if you put a hotter plug in it may cause a backfire also.
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Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Re: 305 backfire through carb
I would concur with a fuel issue at the carb, or some other problem with the fueling. Banging out the intake is usually caused by a lean, slow burning mixture that's still in the process of burning when the intake valve opens for the next intake stroke. That then sets off all the fuel in the intake, causing a backfire through the carb. In this case plugs shouldn't have that much effect. Since it runs ok at idle, the timing is probably ok and the problem is likely elsewhere.
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Car: 87 sport coupe
Engine: 305
Transmission: 700R4
Axle/Gears: 2.73
Re: 305 backfire through carb
If this helps any i adjusted the valves may have went to far down on cam but there is no obvious tick coming from valves. It has a new fuel pump but it had been sitting a few yrs but i pumped all the old bad gas out. Last time i tried to drive down the road it backfired alot through carb and cut off and couldnt get started again.
#7
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Car: 1986 pontiac trans am ws6
Engine: 305 tpi
Transmission: 700r4
Re: 305 backfire through carb
mine pops through throttle body, I might have a worn lobe or two on my cam?!?!
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#8
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Re: 305 backfire through carb
Or, a fueling problem; low fuel pressure, clogged filter, dirty injector, etc.
I'd start my investigation there, before messing with a cam.
I'd start my investigation there, before messing with a cam.
#9
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Car: 1986 pontiac trans am ws6
Engine: 305 tpi
Transmission: 700r4
Re: 305 backfire through carb
i bought new accel injectors 21 lbs, cold air intake, k&n air filter, checked my fuel pressure 47 lbs at rail, new fuel pump, new fuel filter, holley adjustable fuel pressure regulator,new temp sensor, electronic temp control, throttle pos sensor, new iac, new cap, plugs, wires, new mass air sensor.
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