I am looking for an answer on why most, if not all, trucks outfitted with Impco LP with model J converters start hard on intitial start up. Once they have been started once they start immediately after that.
My first impression was that the vacuum needs to build up first before the fuel lock opens up which then sends fuel to the converter and the reason that the truck starts quickly after that is that there is now gas in the converter whereas on initial start up the gas in the converter has bled off.
Well that theory is blown because on initial start up when the engine cranks and cranks if you push the "choke" button on the converter it is hard which signifies that there is gas in the converter.
So why does it crank and crank on intitial start up and start immediately subsequent to that?