This is for a 1990 740 with the rex-regina system.

I have a fuel pressure gauge spliced permanently into my fuel line. The gauge is located right before the fuel rail, but after the filter, and it's under the hood. The connection is tight and not leaking so the pressure reading is correct.

With the car warmed up and idling smoothly at around 750RPM like it should be, the pressure reading is about 30 PSI only. I've been looking around and have been unable to find in the FAQ what the correct pressure should be on a regina fuel injection system. It mentions that on an LH 2.4 system it should be approximately 300 kPA, which translates to roughly 44PSI.

Is it supposed to be the same on regina? I remember others saying they have replaced their regina fuel pressure regulator with an equivalent from Bosch and it worked fine, and that the specs call for 44PSI for both.

If this is the case, what is causing this low pressure in my system? It's not the FPR because I have two FPRs here and have tried both with the same results.

Is it the fuel pump?? I'm going to replace the fuel filter also just to eliminate that.... but I guess I'm just seeking some kind of confirmation. It's probably the fuel pump, right?

Thanks much.
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Ken
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'
Click here for the 700/900 FAQ