Fuel leak

[Mark-8rlbe]

Evening all.
Not worked on a fuel injection set up before, so am treading carefully.
I have a braided hose that drips fuel. Tightened the clips either end and that seems to make it worse.
Was going to launch in and replace the hose, but wondered whether the system would still be under pressure (even with a leak) and spray fuel all over the place.
Cheers in advance.
Mark

[RCK974X]

As far as I know all injection systems maintain some pressure in the line to stop bubbles when engine hot.
so you will need something to catch the fuel in.

Are they steel clips ? I ask because the small ones often go 'out of round' when you tighten them, and so still leak.

I found some neat nylon ones which tighten with pliers and can be undone, and they work very well....

[mrzigazaga]

Hi mate


Depressurising the system is best done cold...There might be a small amount to contain...What hoses are you thinking of changing?

[adam quantrill]

You can take off the return pipe at the engine end and there will be a few cc of fuel let go which a rag can easily soak up.

I don't like these braided hoses because the rubber underneath can perish and you can't see.

[Mark-8rlbe]

RCK974X said:

As far as I know all injection systems maintain some pressure in the line to stop bubbles when engine hot.
so you will need something to catch the fuel in.

Are they steel clips ? I ask because the small ones often go 'out of round' when you tighten them, and so still leak.

I found some neat nylon ones which tighten with pliers and can be undone, and they work very well....

That's interesting - as I tightened the jubilee clip, it seemed to make the leak worse. I wonder whether they are distorting?

Maybe I can try some proper clips first. Where did you find the clips?

Cheers

Mark

[Mark-8rlbe]

mrzigazaga said:

Hi mate


Depressurising the system is best done cold...There might be a small amount to contain...What hoses are you thinking of changing?

I don't know the technical description. But, it is just under the plenum. If the nylon clips don't work, I will post a picture.

Cheers.

[Mark-8rlbe]

adam quantrill said:

You can take off the return pipe at the engine end and there will be a few cc of fuel let go which a rag can easily soak up.

I don't like these braided hoses because the rubber underneath can perish and you can't see.

OK cheers. I was just worried about it spraying all over the shop. Should be ok with caution.

[mrzigazaga]

Hi Mate


If its the fuel rail hoses then the plenum will need to come off...They can be a pain to do..Make sure you use a good quality high pressure rated hose...Gates is a good choice...Ill see if I can dig out part numbers.

I had most of my run from the pump changed to kunifer copper...The parts to the pump and rail are good quality fuel hose.

be careful as there is a lot of hose on the shelf that may only be a year or so old but absolutely no good for the high ethanol content in modern fuel, I think they were struggling to keep up TBH....

Ziga

[RCK974X]

At small diameters, the 'worm screw' type jubilee clip doesn't work well, as the screw bit doesn't bend, so clip goes oval. Ok for bigger dia rad hoses, but not little fuel or vacuum ones.

Here is an example image of the nylon ones. (look for 'nylon hose clips' on ebay)


As you can see, this tightens with pliers, (or fingers to start with) and can be undone by pushing the 'jaws' out sideways. They work a hell of a lot better with small hoses,as they stay circular, but they don't have the same clamp range as a jubilee clip, so you do need the right size ....

Actually they make big diameter ones too, which would work for rad hoses...

Edited by RCK974X on Tuesday 27th June 05:50

[SEvans]

If you are having problems with the Jubilee clips then these are another option. Use them on mine and had no problems.
http://www.demon-tweeks.co.uk/performance/fuel-fit...
Cheers Steve

[mrzigazaga]

Always buy good quality clips for fuel hoses...I used the "Norma" clips with a rolled edge that don't cut into the hose if over tightened.

I had a reputable TVR garage change my fuel rail hoses and a year later they were leaking fuel into the vee...

If you have to remove the plenum please make sure that you use a good sealant and that you allow it to go off before running the car.

While its off its good practice to clean the idle control valve...(The alloy cup on the screen side of plenum...Do not remove the TPS ( Throttle pot sensor) which is connected to the throttle butterfly spindle.

[Mark-8rlbe]

Thanks all. Sound advice as always!