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MG MGB GT V8 Factory Originals Technical - EFI fuel pressure

Does anyone know the factory or optimum fuel pressure setting (in lbs. per sq. inch)for the Rover hot wire system?
Jim Stuart

Jim, 39-41 psi.
Glenn Towery

Thanks, Glenn, I had guessed 40 lbs., so I was in the ball park.

For those who want an adjustible fuel pressure regulator for a Rover EFI system, ACCEL makes one that is almost a perfect fit, $82.00 at Summit, add in a fuel pressure gauge 0-60 lbs, oil filled, Summit brand, for another $17.00, and you are in buisness.

The Accel unit fits the original fuel rail with a bit of filing at the mount, and bolts up just as the original did.

You will have tobraze or silver solder a fitting to the fuel rail to mount the gauge, or figure out a way to put a fitting in the return line. I silver soldered a female fitting on the rail siting the gauge where it could be seen from one side.
Jim Suart

Doesn't the hot wire system use a variable rate pressure regulator? What's the benefit of the summit one?
Regards
Tony
Tony Bates

Jim,
Is this the item?
ACC-74560
Regards
Tony
Tony Bates

I've been toying with going to a smaller fuel injector, and increading the fuel pressure so when the injector does fire, it atomizes the fuel more efficiently. This 'should' result in better power and fuel economy too.

Thoughts?
Justin

The Rover hot wire system uses a fixed regulator, as does the earlier "flapper" system. A rising rate regulator is a common upgrade for the "flapper" system, but does not work for the hot wire set up.
What is discussed here is adjustible, but it does not vary pressure from the adjusted value. Rising rate regulators vary pressure based upon engine demand. The hot wire system varies the length of the injector pulses.

Tony, you have the correct number. Thanks, I meant to include it. That model is described as a fuel rail mount, which it is, rather than some which mount on the fire wall or other location.

You can install the new regulator in about 15 min. once you have remove the fuel rail. Installing the gauge takes a bit more time if you add the fitting to the rail.

Justin, It should work, but will you starve the engine at WOT? I am not knowledgable enough to answer this question. The car manufacturers don't play that way, and economy is a major objective with them.
jim Stuart

Auto manufacturers are bulls in china shops. Ever seen how crappy of a job they do when building cylinder heads? There's TONS of power that can be had just by cleaning up the ports. Big 3 could probably get away with building smaller capacity, more fuel efficient engines if they did a better job engineering them, and building them to more efficiently use what's there.

One of my friends at church does product development at Bosch, and she specializes in fuel injectors. I asked her about it and she said she can get some test equipment so we can play around with it and see what happens.

Living in Detroit has benefits. =)
Justin

This thread was discussed between 05/08/2006 and 08/08/2006

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