18 stoner · Mar 10, 2018

Here goes, looking for an easy answer if anyone has had this one before! Lol!

Disco tank pump will scream when ignition is put on like when bleeding a new filter through.

The lower the fuel in the tank, the worse it is. If you don’t wait for the pump scream to subside before starting, it will often fire then stop. After much cranking over it will start!

I’m assuming it’s getting air in somewhere, hoping the fuel level variation may point any of you in the right direction?

Any suggestions?

Cheers, Pete.

Toseland · Mar 10, 2018

Is there an air leak?

If the fuel system is allowed to drain back into the tank because of the air leak it becomes hard to start as it has to repressurise, which might account for the insane pump sound, and also the cutting out if the fuel isn't present.

I would check for any loose clips or perished hoses first and see if they they any sifference

Toseland · Mar 10, 2018

Because my phone hates me, it would be indicative of the position of the leak only up to the level of fuel in the tank.

It's difficult to explain but fluid will find it's level so if you have a tank full of fuel the fuel level will only drain back in the lines until it reaches the same level as the top of the tank, the leak will be above this,

With an empty tank there is less fuel and hence the lines can drain more. And the problem will be more prevalent.

This will also be more pronounced if the vehicle is parked with the (uk) drivers side raised, say on a kerb or with the engine raised above the tank as fuel can run back Into it regardless of the Lev of the fuel in the tank.

Fuel might also be muffling the pump a little.

18 stoner · Mar 10, 2018

Toseland said:
Because my phone hates me, it would be indicative of the position of the leak only up to the level of fuel in the tank.

It's difficult to explain but fluid will find it's level so if you have a tank full of fuel the fuel level will only drain back in the lines until it reaches the same level as the top of the tank, the leak will be above this,

With an empty tank there is less fuel and hence the lines can drain more. And the problem will be more prevalent.

This will also be more pronounced if the vehicle is parked with the (uk) drivers side raised, say on a kerb or with the engine raised above the tank as fuel can run back Into it regardless of the Lev of the fuel in the tank.

Fuel might also be muffling the pump a little.

Yeh cheers Toseland. I’d sort of got that far to be honest, a bit more to the story is;

We’ve had the tank out (to weld the chassis leg) and fitted new pipes while it was out. Removal and refitting of the tank and fitting new pipes hasn’t altered the symptoms in any way.

Do you think it could be the pump itself?

ShaneMitchinson · Mar 10, 2018

I think when you are looking in at the fuel filter in the wheel well. The back left line has a 1 way valve in it, I believe this fails and either allows air in or for the line to drain, hence needing to bleed it each time. It's about £12 for the part so worth checking it.

Shane

jamesmartin · Mar 10, 2018

i would look at doing injector seals ,replace air bleed valve in filter head rear outer pipe connector

ShaneMitchinson · Mar 10, 2018

ShaneMitchinson said:
I think when you are looking in at the fuel filter in the wheel well. The back left line has a 1 way valve in it, I believe this fails and either allows air in or for the line to drain, hence needing to bleed it each time. It's about £12 for the part so worth checking it.

Shane

jamesmartin said:
i would look at doing injector seals ,replace air bleed valve in filter head rear outer pipe connector

Or the outer my bad

Evan farmer · Mar 10, 2018

on the filter head there is a none return valve if there isnt one there then fit new one and fit the orange thing if possible

18 stoner · Mar 15, 2018

Cheers for the help guys!

Ordered the filter/one way valve thingy, also the small jet insert for the inner pipe fitting too.

On fitting I removed both fittings to the rear of the filter head & neither had inserts in them! Obviously there’s been issues in the past and someone pulled the guts of them out!

Now fitted it seems massively better. Not sure it’s totally cured as occasionally on start up the pump still squeals but hasn’t needed a bleed through yet.

Only had today to try it out so guess time will tell if it’s fully cured but feeling hopeful!

Once again, huge thanks to you all for your input

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