How to Rebuild a Vortech FMU 

No the inserts came in a seperate kit I had to buy. How fmu's work is all over the internet. Basically it raises fuel pressure if using the 12:1 disc 12 psi for every 1 psi of boost pressure from the turbo. Or 4 psi fuel pressure for every 1 pound of boost using the 4:1 disc. Selection all depends on how big your injectors are. The best thing is to choose the disc based off what your air fuel gauge is telling you. If you are lean using an 8:1 then try the 10:1

Thank you for your reply and your tutorial. Just what I needed. Just got a new fuel pressure gauge and notice my pressure isn't rising as should. I guess first is to check for vacuum leaks. And then take a look at the FMU internals? Also, could I test the FMU by directly pressuring the line with an air compressor?

The reason they say that is to scare people out of fixing it themselves. I took mine apart and back together and it never leaked. They charge around $40-$60 to rebuild the FMU just in labor and another $40 in parts. Its a rip off tactic. Thats why I made this video after finding out for myself what a scam it is to try help others out. You can see for yourself in the video how basic the bottom portion is in there.

I picked up a used FMU, this helped, thank you. Do you know where I can get the (3) brass fittings? The previous owner removed them. Or do you know what size they are??

Yes you can use air pressure but dont do more pressure than what it will see on the car. Make sure the FMU is installed in the return line and that you have no fuel leaks and that the fuel pump can actually deliver the pressure.

Mine leaks like crazy from around the diaphragm on the bottom. I assume that means that my o-ring is bad or that the bolts came loose inside?

Thanks 🙏👍

Did you have to contact Vortech directly for these replacement parts? I can't seem to find parts/rebuild kit on their site or anywhere online. Thanks!

Do we know if the Blox parts are interchangeable with Vortec?

Im not sure mine does not have a spring inside it at all. I imagine it went above or below the plunger.

Took my knockoff apart cause it wasn't working. You're gonna love this. It had NO CALIBRATION DISC. was sold as a 12:1. It had the outer ring from a 10:1. The bottom diaphragm was completely destroyed because whatever Chinese fuck put it together SWITCHED THE PLACES OF THE TWO DIAPHRAGMS. The valve punctured it. Lol I just ordered a begi brand 2025 now.

could you measure the diameter of your 12:1 disk? im going to try and make my own disk :)

are u using some sort of noise reduction? its super weird and confusing...

On the Vortech re-calibration instructions. They say not to loosen the 4 bolts that hold the valve or it will have to be replaced. Is that true? What is the reasoning behind that.

Will this FMU work on a Supercharger (b16a honda engine)