What fuel pressure for 9PSI?

[jhilb]

What fuel pressure should I be running with 42lb injectors and 9PSI?

 

[Daggar]

Moved thread in order to gain better chances for responses. Topic doesn't relate directly to electronic tuning of the ECM.

The answer to your question though, would be "stock fuel pressures". Electronic custom tuning is required to make 42 lb injectors work correctly with the Fox family of processors.

 

[jhilb]

Thanks for the move.

I am guessing around 40PSI with vacuum off? That sound right to anyone?

I just checked it and it was at 34PSI vacuum off and was running like cRap. It's no wonder. Whenever I tipped into the gas it'd bog.

So does 40PSI sound right to anyone?

 

[getusummm]

I am running around 42 or so vac off. I am hooking up a fuel pressure gauge in the car today, so I can see what it does with oost pressure. AS mentioned above, you really need a custom tune to take full advantage of the combo. I will be getting a tweecer soon.

 

[Rick 91GT]

I would start at 38psi vac off and go from there, reading the plugs is crucial.

 

[jhilb]

Thansk guys. Yes, I actually am working with a Tweecer now. Car seemed choppy. I turns out the fuel pressure was at 34psi. Duh.

So I upped it to 42, much better now.