65 smallblock will not idle

[Rick Gouda]

My 65 small block, 327/250 is still having a real problem. It will only run at higher rpm. It continues to feel as though it is missing even at higher rpm. The carb was just rebuilt with no positve effect. It has a new distributor, I just set the dwell to 28(spec is 28-32). The timing, vacuum advance were previously set and the car worked fine. It has set for the majority of 2 years. The gasoline is of varying vintage. New plug wires, plugs. At cranking it will occasionally backfire and shoot white smoke out of the carb. Any educated ideas? Thanks for your inputs.

Rick

[Duke W.]

Re: 65 smallblock will not idle

Could be a lot of things - distributor, coil, plug wires and/or indexing, ballast,timing, etc. An oscilloscope analysis of the ignition system would be a good idea, and if it checks out the next likely suspect is the fuel system.

When the WCFB was rebuilt was a new filter installed in the fuel inlet housing? What is the condition and age of the fuel pump? Has the fuel tank ever been removed for inspection?

Cars that sit can be afflicted with varnish buildup in the fuel system, so
a thorough systematic inspection of the fuel system is in order if the igntion system checks out.

Duke

[Duke W.]

Re: 65 smallblock will not idle

Could be a lot of things - distributor, coil, plug wires and/or indexing, ballast,timing, etc. An oscilloscope analysis of the ignition system would be a good idea, and if it checks out the next likely suspect is the fuel system.

When the WCFB was rebuilt was a new filter installed in the fuel inlet housing? What is the condition and age of the fuel pump? Has the fuel tank ever been removed for inspection?

Cars that sit can be afflicted with varnish buildup in the fuel system, so
a thorough systematic inspection of the fuel system is in order if the igntion system checks out.

Duke

[Wayne C.]

Re: 65 smallblock will not idle

"The timing, vacuum advance were previously set..."

When? Sure sounds like timing or dirty fuel. It might also be worth setting the engine at TDC on #1 cylinder and checking to see if the timing mark on the balancer points at the zero mark, as the outer part of the balancer has been known to slip if the rubber deteriorates.

[Wayne C.]

Re: 65 smallblock will not idle

"The timing, vacuum advance were previously set..."

When? Sure sounds like timing or dirty fuel. It might also be worth setting the engine at TDC on #1 cylinder and checking to see if the timing mark on the balancer points at the zero mark, as the outer part of the balancer has been known to slip if the rubber deteriorates.

[Dave Henderson]

Re: 65 smallblock will not idle

Recheck plugs for fouling and check carb for flooding. Original ignition systems dont generate enough spark to keep the plugs unfouled sometimes.

[Dave Henderson]

Re: 65 smallblock will not idle

Recheck plugs for fouling and check carb for flooding. Original ignition systems dont generate enough spark to keep the plugs unfouled sometimes.

[Shane G.]

Re: 65 smallblock will not idle

I'm no expert, but it sure sounds like a vacuumn leak to me. I had the same symptoms once. I used the "unlit propane torch" technique and found a big old leak. It is at least worth a shot before you start ripping stuff apart.

[Shane G.]

Re: 65 smallblock will not idle

I'm no expert, but it sure sounds like a vacuumn leak to me. I had the same symptoms once. I used the "unlit propane torch" technique and found a big old leak. It is at least worth a shot before you start ripping stuff apart.