67 newport carb issue

[damnuglynewport]

67 Newport Custom 383 Factory 4 barrel
idles and runs great but when you punch it seems to hesitate and cut out but if you gradually floor it over say 5 seconds its fine to full throttle ! Any ideas

 

[Davea Lux]

67 Newport Custom 383 Factory 4 barrel
idles and runs great but when you punch it seems to hesitate and cut out but if you gradually floor it over say 5 seconds its fine to full throttle ! Any ideas

If you still have the factory Carter 4BBL, the most likely cause is moonshine blend fuel has probably eaten up the accelerator pump. The older ones were leather and ethanol blended fuel destroys them quickly, I would start with a carb kit. Also possible but less likely, you would want to check the resistance on your points as weak spark will cause poor performance under full load conditions. Also check the fuel filter to be sure it is not plugged and starving the engine for fuel. Also check the heat riser to be sure it is not stuck as that can cause the carb to boil resulting in poor performance.

Dave

 

[damnuglynewport]

Wow Great !
Its not the points i guess it was changed to electronic ignition ?
I don't know much about these cars so its awesome to have great people like this

 

[CBODY67]

That particular OEM AFB is about 525cfm, with full-manual secondaries (as the one on my '67 Newport was), so hard to bog the engine with WOT from idle. So, I'll concur on the accel pump being the main issue.

CBODY67

 

[67Monaco]

I chased my hesitation with the Carter AVS for years. After several carb rebuilds, it ended up being timing. Once I used the vacuum gauge/timing light method to set everything the hesitation is gone. Matter of fact it hits like a hammer out of the hole now.