Most of us don't give them a lot of thought, but the solenoids in your nitrous oxide system are critical components that must be kept in good working order. These electromechanical valves control the flow of nitrous and fuel to your engine, so ifthey're malfunctioning, performance suffers. The internal plunger wears with usage and exposure to fuel vapors-this happens in both solenoids, but the nitrous side, being under pressure, sees the most plunger wear. Depending on how it wears, it can leak, causing a pressure drop in the system; on the other hand, the plunger can also swell and distort, blocking the flow of nitrous and causing an overrich mixture. NOS recommends that you examine the plunger seal in the nitrous solenoid every 20-30 pounds of usage-more often if you're using a controller that frequently cycles the solenoid. It's doesn't take long to do, and it's an easy way to help maintain peak nitrous system performance.
You don't have to take the...
You don't have to take the solenoid off your car to disassemble and inspect it, but we did to make things easy. You should, of course, make sure there's no nitrous in the system before you start working on the solenoid. The rebuild kit itself is a pretty simple proposition; it includes an O-ring seal, a plunger spring, a plunger, and a spanner nut.
The first step was to remove...
The first step was to remove the solenoid coil retaining nut, then slide the coil itself off of the solenoid stem. The two washers sitting on the solenoid base will be reused so we set them aside for the moment.
We placed the solenoid spanner...
We placed the solenoid spanner nut over the stem and onto the stem seat; it has drive dowels that engage with the holes in the stem seat; the nut can then be turned, loosening the stem.
Once the solenoid stem was...
Once the solenoid stem was loose, it came away easily from the solenoid base.
At this point, the plunger...
At this point, the plunger was removed from the stem and examined. The surface should be flat and resilient; it will probably have some indentation from the base, but it shouldn't be too deep. Our example was worn down and dried out, but plungers can also swell-either case calls for replacement.
After making sure the solenoid...
After making sure the solenoid stem and base were clean and dry, we fitted the new plunger with the new spring included in the kit then slid it into the stem.
After the stem was outfitted...
After the stem was outfitted with a new O-ring seal, we rejoined it to the base and tightened it down with the spanner nut.
All that was left was to put...
All that was left was to put the coil back on the solenoid stem and tighten the retaining nut. With new internals in place, this solenoid is refreshed and ready to run.