Lift pump and fuel filter

[neil00001]

Hi all,

Just fishing for some advice....as usual......

My Disco is loosing power at 3000rpm, I suspect fuel filter, but what are the symtoms leading up to a lift pump failure apart

from it wont start........? thanks

Cheers,

Neil

[LandyManLuke]

Normally, if the lift pump fails, the engine will run at tick over but die as soon as much throttle is applied.

[Orgasmic Farmer]

A common problem on TDis is delamination of the pipes from Intercooler to turbo. Might be worth checking this. ?

[nige90]

Normally, if the lift pump fails, the engine will run at tick over but die as soon as much throttle is applied.

Have to disagree here. The injection pump is quite capable of pulling sufficient fuel

to run normally. What it doesn't do very well is pull air so it'll be a sod to bleed after

a filter change.

I base this on the fact my lift pump has been bust for months and the car runs fine.

I only found out it had gone after a filter change. I used a syringe to suck the air out

the filter and intended to fit new pump........ I really will have to get one

Also, some vehicles, Vauxhall Astra for example, do not have lift pumps at all.

However, a bunged up filter really stifle performance.

[RRX]

swap the diesel filter and see if it runs any better , mine picked up a bit after replacing my lift pump as it had died so if yours is high mileage i would replace it aswell

[LandyManLuke]

Have to disagree here. The injection pump is quite capable of pulling sufficient fuel

to run normally. What it doesn't do very well is pull air so it'll be a sod to bleed after

a filter change.

I base this on the fact my lift pump has been bust for months and the car runs fine.

I only found out it had gone after a filter change. I used a syringe to suck the air out

the filter and intended to fit new pump........ I really will have to get one

Also, some vehicles, Vauxhall Astra for example, do not have lift pumps at all.

However, a bunged up filter really stifle performance.

OK, my lift pump broke, the engine ran as i described. Maybe it broke such that it was restricting flow. In fact it did, there was suction on my finger held over the drain hole on the filter (tap removed)

I got home with a fuel can tied to the wing mirror. I ran out of fuel (~3L cereal tub as fuel can) many times, the injection pump self primed fine every time, as you'd expect it to, being gravity (via syphon) fed, in this lash up.

Any fuel restriction is going to limit engine performance, whether that restriction is in the filter, lift pump, fuel lines or tank pick up.

[neil00001]

FIXED,

cleaned out the sediment bowl full of water and scum, and replaced the fuel filter, running better than ever..!

Primed no problem, just ran it for 5 minutes after each unit was cleaned/replaced.

Thanks alot for your input people!

Cheers,

Neil

[rejo]

Thanks .......

[JimAttrill]

Normally, if the lift pump fails you will notice loss of power at high engine speeds. Some people don't notice because they don't drive fast enough.

We even had a TD5 in that would run after a fashion with no fuel pump action at all. Now that is amazing...

[Chriso]

This is really interesting! I have had my 300tdi disco for four years and always thought that it was a little slow at the top end. It pulls great up to 3000 rpm and then runs out of puff.

While servicing the car today I removed the filter and held a container under the filter head. I expected that fuel would rush out from the lift pump when I cranked the engine.

Not a drop!

So I guess the timing pump is pulling fuel from the tank and then becoming starved at 3000 rpm. I always suspected the lift pump because the cranking lever never worked no matter where its' relative position on the cam.

The vehicle has always self primed very quickly after filter changes. I am going to get a new pump and maybe go a bit quicker?

Take care

Chris.

[JimAttrill]

Yes