Hello,

i know I should use the search function, but there are so much conflicting statements about this.

I have a aftermarket turbosmart FPR.

Which one is the right way?

1. Engine off, Fuelpump on - adjust to 36 PSI
2. Engine on, adjust to 36 PSI
3. Engine on, vacuum disconnected from FPR, adjust to 36 PSI

 

I've always done it with the engine on and vaccume line off. Get it to 36psi then reattach vaccume. Never had an issue, whether it's the 'correct' way who knows.

 

option 1 & 3 are nearly equivalent. Option 2 is not. Choose option 1 or 3. I set it with the engine off, so option 1.

The thing that makes this confusing is that the specification in the service manual for fuel pressure on a stock car is at idle (kind of like option 2). It's listed as 27-33 psi. That's on a stock engine with a stock idle speed with stock ports etc etc.

 

One thing not mentioned is the fuel pump speed relay only comes on with a high load and this jumps the voltage up to fuel pump. This increases pressure. Less pressure at idle allows leaner running if tuned for it.

My way is: engine idling, AC on or heavy electrical load, speed relay jumped so full voltage goes to the FP, vacuum hose removed from the FP pressure regulator.

 

What injectors do you have?

 

OEM injectors, why?
I changed the FPR to the turbosmart because it hast a better curve than the mazda one, better for my VE Tuning with adaptronic.

 

Different injectors require different base pressures to function correctly.