I just bought a used top gun nitrous kit and when I tested them they both clicked fine indicating that they are working properly. When I picked them both up the nitrous solenoid was really hot. Almost too hot to touch. After it cooled down I did another test and same thing. Really hot. There is another kit in the garage so the same test was done on those and both stayed cool. Also, they were timed for 10 seconds each so that the test was consistent. I'm thinking that I need a solenoid rebuild kit for the solenoid. Where could someone get a Top Gun rebuild kit?

 

selenoids use a coiled wire that is simply laquered to make the coil of wire more compact. Enigine vibrations are a big culprit in making this laquer chip, rub, or wear off. When it does this you get an internal shortcut or simply "short".

A lot of times the selenoids will still work to some extent, but the ability to do the harder mechanical work is diminished. Say for instance lift the plunger when there is 1000 psi of nitrous behind it.


In any coil some heat is going to occur due to the resistance of the coiled wire, when that resistance is lowered due to the short the heat increases. Some manufacturers purposefully build coils with less wire for costs or a variety of other reasons.

The other set of selenoids you tested, were they top gun also? The heat could be something that won't go away when they get rebuilt (unless they saw the error of their ways and updated the coil). I highly suggest you rebuild to find out.

 

I did some research and found that Top Gun must have went out of business. I tested 4 NOS solenoids and 2 top gun solenoids. The one is the only one getting really hot.