Zex Nitrous Computer

[Pat]

Zack;

Do you have any experience with the repair of the "Purple Box". I noticed one of your MMs has one installed from a picture I saw recently.

I've replaced three of them over the years, only the first one lasted more than a few cycles.

Zex tell's me they don't repair the unit, or stock repair parts. At $225.00 a pop I'm wondering if you or someone else knows of any repair efforts.

I'm contemplating replacing the purple box with two solenoids: one for gasoline and one for nitrous. It will be a manual control operation.

Thanks,

[Zack]

I've only used mine a handful of times with no issues.

I suggest bench testing the unit first. If you have a bad solenoid, first see if it can be disassembled to be cleaned.
If that doesn't work, look for identifiers on the solenoid, than replace individually.

[Zack]

Solenoids in any application are difficult to break.
Maybe something else is wrong.
Bench testing is a good place to start.

[Pat]

That's interesting to note that the solenoids are not necessarily unreliable.

There's a circuit board in the purple box that can also contribute to the problem.

My plan of attack is to activate each solenoid separately with +12 Volts and observe each output with the input connected to compressed air.

If both solenoids pass then the problem is in the circuit board. If I can't fix that, I can hot wire the solenoids and manually control the solenoid operation with toggle or button switch in the cabin.

May save buying replacement solenoids at $60.00 apiece while preserving the mounting and connections.

Chime in if something is wrong with this plan, if OK then I'll report back in a few days.

[Pat]

Thanks Zack for your insight regarding solenoids. I tested both solenoids separately and they passed gas when activated (no pun intended) and remained quiescent with no voltage applied.

It seems I now have a working nitrous system, sans throttle position control. Tomorrow I will complete the re-wiring connections and be ready to go in time for races later in November.

Wasn't it DOOM that used to chant "here Hemi, Hemi, Hemi?

I'm a happy camper.

[Pat]

There is a downside to a manual activated/controlled system. That is to make sure you turn it off when the WOT (or close to it) RPM drops. Otherwise full nitrous will be continue to be applied as the engine unwinds.

I would think this would be a bad thing. I'll have to look into how non-computer control users solve it.

[Zack]

The activation switch is most likely out of adjustment. It is either at the gas pedal or the Throttle Body.