What's the right fuel pressure?

The car is ford escort 1991 1.6 77kw/105HP, CVH engine, EFI.
Autodata says 2.5 bar Haynes "Ford Escort & Orion (Sept 90 - 97)" says 3.0
Haynes #686 (escort up to 1990) says 2.3 to 2.5 (for 1.6 CVH EFI engine)
dunno what to do... it's at 3 bar right now.
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I'll greep out on to, for me, a shakey limb... No experience with the European offerings and I work in PSI rather than bar....
IIRC, 1 bar = 1 atmosphere (or 14~15 psi). Now.... *most* of Fords port fed fuel injectors work in the 40 psi range - a pound here or a pound there isn't the end of the world. All of these have some sort of interactive fuel pressure regulator. Here's why....
A fuel injector nozzle is designed to deliver it's best pattern at a specific pressure drop across the nozzle. This is why fuel pressure at idle (high vacuum) is lower than fuel pressure in high throttle angle/low vacuum situations.... it's all about maintaining that "constant pressure drop".
For a fuel pressure test to have any real meaning, we need to conduct the test when the concern is evident. Many faulty pumps can deliver the required pressure at idle, yet fall flat on their faces during a high fuel requirement condition (higher gear, higher rpm, high throttle angle).
Roughly, the same thing applies to CFI type units... those where there is a single injector.throttle body assembly situated where a carburettor (isn't it nice that I know how to spell it correctly?) would have been. The fuel pressure regulator on these units react to atmospheric pressure rather than manifold vacuum. Again, the idea is to maintain a constant pressure drop across the injector and, once again, the fuel pressure needs to be read when the concern is happening.
FWIW.... I have yet to see any fuel pumps that can be called robust.... they don't like running out of fuel and they don't like pumping against restricted filters for any length of time... I don't know how many times I've seen fuel pumps fail within just a few miles of filter replacement where the old filter was plugged near solid...
Words of caution... when checking fuel pressure while driving... do NOT bring the guage into the cabin.... the last thing anyone needs is for a high pressure fuel leak to develop in an enclosed space. When using a mechanical guage, bring the guage out to the windscreen and use duct tape (also known as gaffers tape) to affix the guage to the glass.

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thanks very much for such a long reply!
40 PSI = 2.75 BAR. mine is currently at 43.5 PSI (3 BAR) The car runs good, little stuttering (will try ultrasonic injector cleaning), but mpg might suffer due to fuel pressure being a bit high (if it is)
you gave me some new thoughts to consider about the fuel pump...
I gave thought to route mechanical fuel pressure gauge to cabin... good thing I gave it up, because while I was drive-testing the pressure, one clamp disengaged spraying something like half a galon all over the engine ... if it was in cabin the car would be a smelly mess for a long time... I was lucky the spark plug cables weren't faulty or the spilled fuel would have ignited...

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I doubt whether a bit of excessive pressure will affect gas mileage, or anything else for that matter. Your car has an oxygen sensor, and the PCM will 'learn' the correct fuel trim for the pressure, as long as it is within the adjustment range. Injector pulse durations will simply be a bit shorter than nominal, and that's it.

it
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engine)
added to thread from a seperate one: stuttering under WOT resolved:

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