fuel pressure regulator

[merlin]

anybody got a working 12v fuel pressure regulator for a 30ne engine ?

[carlton_mad]

yup!!

pm me!!

[merlin]

pm sent mate

[merlin]

any news on regulator mate ?

[carlton_mad]

got one just got to test and ship it!!

pm your addy dude and we can sort it out!!

[bootie3367]

got one just got to test

I have never done this and I have a spare in my garage from a previous 2.6 ( I presume it is the same thing) so how do you test them? Just in case the one I have spare is just junk and taking up valuable space.

Cheers
Jon

[carlton_mad]

its a bit more complicated with the 2.6 and 24v regs because they are fixed to the rail. The way to test the 12v one is simply to fit it!! its a separate unit and with my fuel rail its a nice and easy remove and refit and to see if it works just feed the return side into a bottle and away you go!! (in theory at least!!) I think the fixed ones are changeable via four screws but not too sure(never tried!)

[Murph]

They certainly look to be removeable.

[melinx]

On my C26NE, the FPR is held on by 4 screws (Torqz I think); but it looks as if it would be difficult, if not impossible to remove from under the inlet manifold once unbolted.

In fact, TIS says to remove the fuel distribution pipe complete with injectors to replace the FPR

[bootie3367]

The spare one I have is a complete rail which is why I was asking. Yes your right it is difficult to do when fitted....
As it's a regulator, what are the specs, if any or is it more of a damper than a regulator, I mean what exactly does it do? Does it damp the pulses from the fuel pump or can it be adjusted (i.e. regulated)?

[melinx]

As it's a regulator, what are the specs, if any or is it more of a damper than a regulator, I mean what exactly does it do? Does it damp the pulses from the fuel pump or can it be adjusted (i.e. regulated)?

I think that the 3.0 litre one provides a slightly higher pressure than the 2.6 and it is not a damper,
the damper is a separate unit also bolted to the fuel rail.

The pressure regulator is there to provide a constant fuel pressure to the injectors and since the pressure would vary with manifold vacuum, it compensates for this with a feed to the inlet manifold via a small rubber pipe off the top of the regulator which otherwise is non adjustable.

[melinx]

I've got it wrong It's the earlier versions using the ML 4.1 electronic control that uses the slightly higher fuel pressure at 3.1 to 3.3 bar. wide open throttle.

The Motronic M1.5 uses 2.5 to 3.0 bar wide open throttle.

[bootie3367]

Thanks for that, now all I need to know is, is it possible to test these off the rail, as a stand alone regulator just to ensure it works so I can then keep it as a spare should the existing one fail, not that I think it will, but.....?

[melinx]

The only way I can think of is : -

Leave it on the rail, make sure that all the injectors are plugged into the rail with their retaining clips; attach an air pump to the fuel inlet pipe somehow.

The pressure testing valve on the end of the rail is a non standard Schrader size, but unscrewing the valve from inside should enable you to put a pressure gauge on it using a bit of rubber pipe and some hose clips.

Start pumping and see what pressure it starts to vent out of the fuel return pipe, also make sure that no air is leaking out of the manifold vacuum pipe attachment on top of the regulator because that would indicate a split diaphragm which would allow fuel straight into the inlet manifold

[bootie3367]

That sounds straight forward enough.

we do a lot of that on here with our fuel transfer hoses. I just need to figure out what attachements/fittings I need.
Thanks for that Mel.

[melinx]

Further thoughts on this one Jon : -

It should simplify the test if you leave the Schrader valve alone and use something like a foot pump or one of those small electrical pumps with an ACCURATE gauge on it.

You should not be able to get the pressure higher than the regulator is set to because it will open and vent through the fuel return pipe when the operating pressure is achieved.

I stress ACCURATE gauge because every foot/electric pump I've used is anywhere between +/- 10 psi in error.

[bootie3367]

No problem getting accurate guages, the one's we use are all oil filled and calibrated every year or brand new (I would only 'borrow' it)

Would be an interesting experiment to setup though. If I have any spare time I will have a go.

[melinx]

If I have any spare time I will have a go.

I wont hold my breath then