Fuel pressure regulating valve

[Chas54]

Hello

I was wondering if anyone had a figure for the vacuum pressure at which the fuel reg valve would open.

I have the fuel reg valve off as I have sent the injectors away for cleaning and testing. On the bench I have pulled as much vacuum as I can on the actuator at about -700mbar. I had filled the petrol side of the valve with a light oil and expected the valve to pass the fluid under vacuum at some point. Mine doesn't yet . I am wonder if the valve is stuck or I need to find a method of achieving a greater vacuum /

I had trouble with running a little rich so I am considering changing this item .

I also haven't yet figured out what holds the petrol inlet pipe fitting on the end of the fuel rail. This is the bit between the fuel rail and the pipeworks union , It doesn't seem to unscrew but turns . Is it just a tight O ring?

Any info greatly appreciated

charlie

[Chas54]

Woops

I guess I should have trawled through the digital manual a bit better. Ive found a figure of 50kpa .
I suspect I made need to pressurise the fuel side to 30-55 psi and then try pull the vacuum.

I notice the fuel inlet pipe fitting is "staked" to the injector rail according to the same write up. I think that may be some internal swaging I cant see.
It seems a little loose to be petrol tight to me though.


charlie

[John_W]

As to the connection to the fuel rail, do you mean the part shown on point 5 of this: http://wikilec.com/view/Fuel_injectors ?

If so it is an O-ring.

[Simon_P]

I was wondering if anyone had a figure for the vacuum pressure at which the fuel reg valve would open.

Not sure if you have seen the description of how it works - it isn't open or closed it is variable, designed to keep the pressure differential between the air and fuel the same.

Just an 'O' ring and the pipe is loose.

[Chas54]

Thanks guys

Ive tested the regulating valve by putting 40psi on the petrol inlet port and then pulled a vacuum on the diaphragm, and it does work. Its not a calibration test, just proof it is capable of operation.

The write up in the manual does say the valve is sping regulated and the vacuum is the assistance required at the varied manifold pressures. I think I couldn't get it to open under vacuum alone, it needed the simulated petrol pressure.

The fitting I am unsure of is on the fuel rail at the opposite end to the reg valve. It has threads to allow the petrol inlet pipe to attach but it must be pressed into the aluminium rail somehow.
It isn't a tight fit though. it would turn with a spanner. I am worried that now I have disturbed it, it may leak and I cant see how its held in.

Thanks for comments

Charlie

[Chas54]

I am reassembling after having the injectors cleaned and tested.

I cant for the life of me work out what sits in the little plastic support that is pushed into the steel strip pressing on the fuel rail.

The support would be for either a cable or vacuum hose and is in the middle of the fuel rail and facing towards the rear of the engine, ie the opposite side to what the electrical connection are on the injectors.

Anyone know what this holds ?

regards

Charlie

STOP PRESS
Now ive ventured into the freezing garage and poked the clip along the rail, its pretty obvious it holds the fuel pipe steady under the plenum . Although I had to remove a cable from number 2 injector to slide it along, the pipe dropped straight in with a satisfying click