If you follow the hose from the propane tank, it should go to either a little electric solenoid or a larger valve assy with a vacuum line attached, from there it should go to the regulator which will either be mounted in the thermostat housing or a stand alone unit. To help I need that information first.
As far as the spark- it needs to be bright blue & jump a distance of at least 3/8" or better when the spark plug wire is held close to a known good ground (cyl head bolt, etc). If it's orange or yellow then the spark is weak & will cause issues. I would suggest a complete tune up if your spark's yellow. Does your dist cap screw down to the distributor or have clips?
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.