1963 327/300 Random Carb Pop
07-25-2016, 11:02 PM
#1
1963 327/300 Random Carb Pop
I was driving my 63 SWC today for first time in a long time. Every so often, I would get a back fire type pop from carb. It wasn't a consistent thing, it came at random and at different rpm's too. Usually in between shifts but sometimes not. New plugs, pertronix, timing and vacuum set to 1963 Corvette specs, carb cleaned and set up, new air filter and cleaned carb. Rebuilt fuel pump, water pump and changed belts.
I didn't change fuel filter yet, I do have it. The fuel is about 5 months old but I always use Sta-bil and top up a gallon or two fresh every month as I don't like driving this SWC too much, too much attention. Car is 100% matching numbers and all stock. Still can't get to fixing gas pedal linkage sticking as my back is terrible. I am running 2 springs on front of carb to pull it back to 600 rpm's. That shouldn't give me popping. Thoughts?
Thanks
Jax
1963 SWC 327/300 4spd
I didn't change fuel filter yet, I do have it. The fuel is about 5 months old but I always use Sta-bil and top up a gallon or two fresh every month as I don't like driving this SWC too much, too much attention. Car is 100% matching numbers and all stock. Still can't get to fixing gas pedal linkage sticking as my back is terrible. I am running 2 springs on front of carb to pull it back to 600 rpm's. That shouldn't give me popping. Thoughts?
Thanks
Jax
1963 SWC 327/300 4spd
07-25-2016, 11:16 PM
#2
Team Owner
Plug wires?
07-26-2016, 04:32 AM
#3
Team Owner
Ignition or lean air/fuel mixture.
If it was in between shifts when you're accelerating into the higher gear it could be carb accel pump not delivering enough fuel to transition to cruise circuit... Could also be a vacuum leak (snug the carb down a bit).
If you can live with it that long, I'd run that tank of fuel out...sounds like you've got a lot going on there...with the different goo that's been added and the time its sat.
If it was in between shifts when you're accelerating into the higher gear it could be carb accel pump not delivering enough fuel to transition to cruise circuit... Could also be a vacuum leak (snug the carb down a bit).
If you can live with it that long, I'd run that tank of fuel out...sounds like you've got a lot going on there...with the different goo that's been added and the time its sat.
Last edited by Frankie the Fink; 07-26-2016 at 04:33 AM.
07-26-2016, 10:14 AM
#4
Racer
Sounds like you have the fuel and ignition pretty well sorted out. Could be a weak, collapsed, or gummed up lifter. May work itself out with a little driving.
07-26-2016, 08:08 PM
#5
Ignition or lean air/fuel mixture.
If it was in between shifts when you're accelerating into the higher gear it could be carb accel pump not delivering enough fuel to transition to cruise circuit... Could also be a vacuum leak (snug the carb down a bit).
If you can live with it that long, I'd run that tank of fuel out...sounds like you've got a lot going on there...with the different goo that's been added and the time its sat.
If it was in between shifts when you're accelerating into the higher gear it could be carb accel pump not delivering enough fuel to transition to cruise circuit... Could also be a vacuum leak (snug the carb down a bit).
If you can live with it that long, I'd run that tank of fuel out...sounds like you've got a lot going on there...with the different goo that's been added and the time its sat.
07-26-2016, 08:08 PM
#6
Ignition or lean air/fuel mixture.
If it was in between shifts when you're accelerating into the higher gear it could be carb accel pump not delivering enough fuel to transition to cruise circuit... Could also be a vacuum leak (snug the carb down a bit).
If you can live with it that long, I'd run that tank of fuel out...sounds like you've got a lot going on there...with the different goo that's been added and the time its sat.
If it was in between shifts when you're accelerating into the higher gear it could be carb accel pump not delivering enough fuel to transition to cruise circuit... Could also be a vacuum leak (snug the carb down a bit).
If you can live with it that long, I'd run that tank of fuel out...sounds like you've got a lot going on there...with the different goo that's been added and the time its sat.
02-08-2024, 03:27 PM
#7
Instructor
Run the engine with the air cleaner off and see if gas comes out of the carb when it pops, If it does, my experience tells me the Cam’s wasted, Or hopefully as somebody above stated it could just be a lifter, Good luck
02-08-2024, 04:18 PM
#8
Race Director
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Dogmark, This is a 8 yr old post, most likely resolved 8 yrs ago. 
Dennis
Dennis
That’s what I get for not paying attention