13 replies to this topic

[JCLE1999]

Hi all. New to this forum and by no means an expert mechanic so any help with this would be appreciated.

I have a John Cooper LE MPi classic mini which I’ve owned for a few years. The previous owner had a fuel boost valve fitted which I’ve only just got around to removing (I know I should have done it ages ago, they’re awful!)

The problem is I’ve replaced the boost valve with an in-line fuel filter and now the car won’t start. Previously it would start first time. It must be the fuel filter that’s the problem but why????? It’s definitely fitted the right way round and fills with fuel when the key is turned.

Anybody know what’s wrong? Thanks in advance.

[cal844]

What's a fuel boost valve? Does it have any wiring to it?

[JCLE1999]

Also known as a power boost valve. Didn’t have any wiring to it.

[Steve220]

You need them set up, they could be any pressure from factory.

[Bat]

Hi,

So if you took out a fuel pressure regulator why haven't you replaced it with another FPR?

Did it run ok and pass the MOT? If so I don't understand why you took it out in the first place?

Cheers 

[nicklouse]

as above what is regulating/maintaining the fuel pressure now? is the original fuel pressure regulator present and connected?

[JCLE1999]

Ah so it’s not possible to just replace it with a fuel filter? I thought the boost valve was there just to add some kind of boy-racer style minor improvement in power, whilst ruining the fuel consumption and emissions. That’s why I wanted to remove it. I didn’t know it actually performed a function. My lack of mechanical knowledge showing on this one.

[JCLE1999]

And it took a very nice MOT place to pass the car last time. Emissions were very high.

[Steve220]

Not surprised. You've probably had copious amounts of bore wash too.

[Bat]

Hi,

Right then you need a standard MPI fuel pressure regulator or a universal sytec one which is 1:1 not 1.7:1

See which you can get hold of. Either will need some work to fit but the mpione won't need setting up.

Cheers 

[Bat]

Not surprised. You've probably had copious amounts of bore wash too.

 

Hi,

You won't get bore wash if it's setup right.

I'm using one to reduce fuel pressure at light load for the extra large injectors I've fitted.

Cheers 

[Steve220]

Not surprised. You've probably had copious amounts of bore wash too.

Hi,
You won't get bore wash if it's setup right.
I'm using one to reduce fuel pressure at light load for the extra large injectors I've fitted.
Cheers

I'm aware. As the OP's wasn't set up, my concern is any internal damage.

[JCLE1999]

Thanks all. Really appreciate the help. Have re-fitted the power boost valve temporarily until I can get an mpi FPR.

[JCLE1999]

Hi again. Having put the power boost valve back on, exactly as it was before the car now stutters badly up to about 3500 rpm and it’s still not quite right above that. I love my mini and it always ran smoothly before. WHAT HAVE I DONE?????!!!!! Anybody know?