Hi I'm having a weird issue with my corvette regulator. Some info on my build is supercharged LQ9, Walbro 450 with -8 feed and -6 return, Sniper rails, 1000cc (88lb/hr?) injectors. When I have the truck running my regulator is jumping around +/- 5psi and it also wont change the pressure when adjusting the screw. However, it will regulate pressure just fine when I run the fuel pump by itself without the engine running. Stays dead nuts on whatever I set it at. What could be causing this reaction because of the engine running? This is not boost referenced. I was trying to set up boost reference when I noticed the issue.

 

Boost reference and adjustment screw? That doesn't sound like a Corvette regulator.

 

Agree - a Corvette fuel filter/regulator maintains a static 58 psi. It is not adjustable and IMO not recommended for boosted applications. Why? Because when in boost you need more than 58 psi in order to increase volume but also to counter the effects of boost pressure against the tip of the fuel injector on the intake side of the injector.

A scientific principle is that when you increase pressure you reduce volume. So to increase volume the FPR allows the increase in volume while at the same time maintaining a static pressure on the outlet side of fuel injector.

If by chance you are using both together then you need to remove the Corvette filter and instead install a larger (volume capacity) than the stock fuel filter and let the FPR maintain pressure and volume.

https://www.turbosmart.com/news/how-does-an-fpr-work/


Some older model year trucks do have a fuel pressure regulator. Is yours one of them?