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-   -   New to carbed engines, need some SBC misfire help (https://67-72chevytrucks.com/vboard/showthread.php?t=500272)

Fangio 12-27-2011 09:15 PM

New to carbed engines, need some SBC misfire help
 
First time messing with a carburated engine and need some help troubleshooting. Its a 64 lwb with a Chevy 350 with turbo 350 trans. Engine always starts on first crank and idles great but while accelerating at anything greater than half throttle the engine sputters and misfires. If I back off the throttle it continues to accelerate without issue. It has an edelbrock performer 600 with electronic ignition. Previous owner said he installed new spark plugs adjusted valves, and set timing. All the vacuum lines look to be in good shape as do the plug wires. I haven't spent much time looking at it yet but my initial thought is timing. Any other ideas or maybe a good plan of attack? Thanks in advance.

Coley 12-27-2011 09:44 PM

Re: New to carbed engines, need some SBC misfire help
 
Putting a timing light on it is job 1......are you familiar with the procedure and set targets?
Coley

pat565 12-27-2011 09:52 PM

Re: New to carbed engines, need some SBC misfire help
 
I have seen this before

The valves are set too tight!

Fangio 12-27-2011 10:16 PM

Re: New to carbed engines, need some SBC misfire help
 
I am familiar with a timing light and how to use one, just dont have one available at my apartment.

Ill put the valves on the list.

For the time being is there anything else I could check and rule out with a multimeter and basic hand tools?

pat565 12-27-2011 10:25 PM

Re: New to carbed engines, need some SBC misfire help
 
Ported vacumn leak.

sapper4 12-27-2011 11:30 PM

Re: New to carbed engines, need some SBC misfire help
 
I agree with pat565. It is an advance issue, most likely a ported vacuum leak. You can also check your vacuum pot to make sure it doesn't leak.


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