Fuel rail pressure 84 XJS

Can someone share what the normal fuel pressure is for an 84 XJS?


28-30 psi at idle (17" vacuum); 36 psi with no vacuum on “B” regulator.

thank you Robert!!


I found this relatively current post in a search, and, I presume, the fuel rail pressure in a 1983 HE would also be 36 psi with engine off (no vacuum) and fuel pump running - correct?


Yes, that is correct. Best source for EFI is the AJ6 Engineering website- aj6engineering.co.uk

Actually, Google “AJ6 Engineering” and pick the Jagweb result; the column on the left has the topics.

Thank you.

I will check that source out.

With the fuel pump wiring disconnected and 12V to the fuel pump, I get 36 psi engine off and no vacuum.

So I go in another direction - starts and runs with starting fluid, so I know ignition system and other system are good, but have now tracked it down to the fuel pump not working with key on. My investigation continues.

Assume you reset the inertia/impact switch?