305 poofing under load - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*Fast68Chevy* · 11-08-2002, 02:52 PM

ok the 81 305 engine has a problem and i think its valve train related, it idles and revs fine but when you put truck in gear and give it gas to get going it has big popping problem out the exhaust and also out the carb,
when it pops out the carb it makes huge cloud of blue smoke and almost but doesnt kill the engine, it will catch up again till it ka-pops out carb again,
and exhaust popping is a single pop and is not irregular, it happens every cycle- a little less than a second apart.

timing adjustment of any kind doesnt change this symptom at all and the wires and everything look fine,
carb is older model and non ESC, and so is distributor, its older one with vacuum advance.

any idea what could be wrong with this 305 other than needing to be yanked and scrapped ? probably camshaft lobe or valve guide problem i bet.,.

87gmc · 11-08-2002, 03:32 PM

Hmm i think you should just go buy a new engine that would fix all your problems

*Fast68Chevy* · 11-08-2002, 04:19 PM

yeah i think so also, im gonna try one thing though, im gonna tear down the face of the engine down to timing set and put on a new set and swap off the dizzy for a 75-79 one and see how it does then, if no improvement then its time to part the truck out, would be wasting my time doing anything else but that to it. i dont have any better V-8 engines than that right now that would go in without headache and the truck has more rust out problems then originally seen, and fuel tank problems am running off a fuelk can on floorboard,.

thanks

11-08-2002, 02:52 PM	#1
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	305 poofing under load ok the 81 305 engine has a problem and i think its valve train related, it idles and revs fine but when you put truck in gear and give it gas to get going it has big popping problem out the exhaust and also out the carb, when it pops out the carb it makes huge cloud of blue smoke and almost but doesnt kill the engine, it will catch up again till it ka-pops out carb again, and exhaust popping is a single pop and is not irregular, it happens every cycle- a little less than a second apart. timing adjustment of any kind doesnt change this symptom at all and the wires and everything look fine, carb is older model and non ESC, and so is distributor, its older one with vacuum advance. any idea what could be wrong with this 305 other than needing to be yanked and scrapped ? probably camshaft lobe or valve guide problem i bet.,.

11-08-2002, 03:32 PM	#2
87gmc I Got My Engine!!!!! Join Date: Oct 2002 Location: Palmer, AK Posts: 254	Hmm i think you should just go buy a new engine that would fix all your problems __________________ F.O.R.D. "F*cked Over Rebuilt Dodge" -+-+-+-+Cameron+-+-+-+- 1987 GMC HIGH SIERRA LWB 1500 32X11.50 383 TBI/Vortec Heads/Intake MSD Ignition Dual Exhaust Custom Pinstriping Sweet interior & stereo http://www.cgalvin29.freehomepage.com

11-08-2002, 04:19 PM	#3
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	yeah i think so also, im gonna try one thing though, im gonna tear down the face of the engine down to timing set and put on a new set and swap off the dizzy for a 75-79 one and see how it does then, if no improvement then its time to part the truck out, would be wasting my time doing anything else but that to it. i dont have any better V-8 engines than that right now that would go in without headache and the truck has more rust out problems then originally seen, and fuel tank problems am running off a fuelk can on floorboard,. thanks



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