Occasional hard start when warm

[smkymntn]

I am still having a hard start issue when warm. Sometimes when it occurs a popping sound is heard in the cab accompanied by a burnt smell. I have to floor it for a minute during cranking and then it usually catches. The thing is other times it fires right up. When cold it fires right up. I am full desmog with carb fan gone also. In using search, some have pointed to a dirty distributor cap- could this be my problem? if so Can I just take the cover off an examine/clean? I have a non usa dist. I live at approx 2500' above sea level- JIMC rebuilt my carb but I did not do a dist recurve. Stock 2f- Any help would be appreciated.

 

[Butt Ugly Chuck]

Sometimes when it occurs a popping sound is heard in the cab accompanied by a burnt smell.

Is your distrubutor still vented as discussed in this "Exploding sound inside the cab" thread (from cab to dissy; from dissy to air cleaner)? Do you think the popping sound could be backfire from the carb? If it's standard backfire, most common cure is timing.

A more likely scenario (for the pop and burnt smell anyway) is unburned gas in the dissy ignited and vented into your cab. See this "vent backfire" thread. Did you retain the VCV between your dissy and aircleaner per this JimC diagram?

By the way, the filter from the dissy in that diagram is in your cab. Not sure that would explain the hard start when warm, but maybe this will help chase it down.

Good luck
Butt

 

[humper99]

...with carb fan gone also.




I think we've found the hard start problem. You'll get bad vapor lock without the carb cooling fan and a hot start problem.

 

[smkymntn]

Ok I tried to reinstall the carb fan. Does anyone know the size of the damn screw? It seems it is different than every other one under the hood.