k well i got a few questions regarding my set up in my truck. its a 302 that only runs on propane, it has a impco model e vaporizer and impco 300a mixer. k well the vacuum line going from the intake manifold to the vaporizer about half way to the vaporizer it has a adapter for another line to go to it, i danno what line goes to it, or if it was just put there to make the line longer??? and another thing on my mixer i have a short line hooked up to it witch has also been blocked off.

i have asked people on the propane forums about this and non of them have any idea to what these lines should be doing because there not to familiar with this set up, but yeah the truck is a 88 F250 with a 302

if any of you have a similar set up your help would be much apreciated. currently the truck runs fine but i have always been wondering about these mystery lines

 

Normally a CA300 mixer does not have any vac lines connected to it. The only exception would be a balance line. If it has a VFF30 Vac lockoff (fuel shutoff) It will have a line for mainifold vac to it. The model E may have a black solenoid screwed into the side of it with a vac line going to manifold vac, that is a start assist (primer/cold start) that uses manifold vac to open the regulator quicker in the start position only.
What kind of problems are you having?
Btw that set-up can be converted to dual fuel fairly easily if the gasoline system is intact

Regards
Gasman

 

k but the vacume line going to the vaporizer, for the cold start prime, there is a fork in the line, witch i capped off, i was just wondering if it has to be connected to another vacuum source and on the bottem of the mixer it has a line that has been capped off too, i am just curious to were they go, it so far runs fine but when its cold it has a hard time to start up

 

Pull the line off of the mixer it does not need to be there.
The SV (start assist) should be screwed into a port on the side of the vapoizer that is below the level of the diaphragm. It should be connected to mainifold vacumn and a 12 volt source that is only hot while cranking. You also need to make sure that the vacumn fuel lock is hooked up to manifold also. If your engine has low cranking vacumn it will be harder to start cold.