Originally Posted by
greenman100
that's high, and probably a product of aftermarket fuel pump on stock regulator.
assuming that you're talking 43psi referenced to atmospheric, as most gauges are. DEFIs have an option to reference to manifold pressure, which is realllly nice for making sure your FPR's rising rate is good
That's one thing I liked about my last Defi gauge system. I always ran in base fuel pressure mode. I could actually watch it drop .2 to .3 bar of pressure at redline!
Every car I've ever seen with any aftermarket pump and stock regulator has had a consistent 3.5bar (50psi) base fuel pressure. That's including my setup above. Personally, I've run Walbro, Tomei, and Supra pumps with the same outcome in base pressure.
The correct way to measure base pressure is to unhook the vac reference line on the top of the fpr, then read the gauge. Alternately, you can just key the car to "ON" without starting it. That will prime the system, and the vac hose will of course have no vac. It may take a little running around because the system only primes for 5 secs.
About the simple gauge setup, the part numbers are as follows:
Marshall pressure gauge for injection: PN: hello Mr AE employee, I need a Marshall pressure guage for injection with 1/8" NPT connection.
Brass fittings = 1/4 NPT "T", 1/4" to 1/8" reducer for gauge, and 2x 5/16" bung/hose to 1/4" NPT fittings. Screw together with teflon tape, enjoy.