Air in fuel on The Estate?

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Air in fuel on The Estate?

Post by Kitch »

So after having it fire up first time after a 3 year lay up yesterday, I've now got the issue where it's getting harder to start and only idles for 30secs before slowly spluttering and cutting out. If you can overcome it by revving it, that tends to eak it out a bit longer, but it always eventually cuts out. It's like the fuel filter bowl isn't filling up and it's just been running on what was left in there since the last time it was parked up.
I've topped up the fuel tank, but it's not that. Could there be sludge in the tank from the stowage?

Can see no visible leaks under the bonnet from any of the diesel pipes. If I prime the system it improves things and makes it easier to start, but it eventually dies again. I'm not even sure which diesel pump it is....I think CAV?

I'm more of a novice on the workings of the diesel engine than a petrol, so any input would be appreciated :)
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Re: Air in fuel on The Estate?

Post by citronut »

which filter does it have one on the wing or on the stat housing,

if the type on the wing with the primmer button on top,

it could be the diaphragm in the primmer head dieing, unlikely though as you say it will prime up with the primmer

also look at the state of the front to rear metal fuel lines, the injector leak off pipes, and any rubber fuel line,

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Re: Air in fuel on The Estate?

Post by Kitch »

Filter's on the inner wing. When I say it primes up, the plunger moves free and easily, but you get dribbles at the bleed screw, rather than diesel gushing out. Does start easier once you've done it (and runs for a minute or so afterwards) though.
Would it be worth whipping the top cover off the filter bowl to see if it's filling up? Would be great if it was just a knackered pipe/hose underneath (one that's really easy to get to too! :lol: )

Leak off pipes look dry, as does the rubber one into the diesel pump. All the injector pipes seem to be dry, so could easily be a supply to the filter issue I guess?
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Re: Air in fuel on The Estate?

Post by rutter123 »

bypass the cav type fuel filter mounted on the inner wing with a simple inline filter, or fit a fuel line supply straight from a can to the pump and a fuel line from the pump return to another container, this will eliminate any fuel supply probs or blocked lines etc etc when i got my tzd i had a similar prob but managed to keep it running this way to get it on the trailer, this was on on a cav/lucas pump.
later i drained the tank and fitted new fuel lines from front to rear, binned the cav fuel filter and fitted 2 inline filters in place of this, has been like this for 70k now with no further probs, changing the inline filters every 5k service. hope your probs are as easy to cure.
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Re: Air in fuel on The Estate?

Post by Mothman »

I am currently running Mollie about using a fuel can in the bulkhead as she has a fractured fuel pipe. I found exactly where the leak was by blowing down the pipe having disconnected it from the pump and saw where fuel was leaking.Now just have to replace the fuel lines. I wonder if you have a pipe thats corroded through?

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Re: Air in fuel on The Estate?

Post by Kitch »

rutter123 wrote:bypass the cav type fuel filter mounted on the inner wing with a simple inline filter, or fit a fuel line supply straight from a can to the pump and a fuel line from the pump return to another container, this will eliminate any fuel supply probs or blocked lines etc etc when i got my tzd i had a similar prob but managed to keep it running this way to get it on the trailer, this was on on a cav/lucas pump.
later i drained the tank and fitted new fuel lines from front to rear, binned the cav fuel filter and fitted 2 inline filters in place of this, has been like this for 70k now with no further probs, changing the inline filters every 5k service. hope your probs are as easy to cure.
That's a good idea! Will help me pinpoint the problem at any rate.

So that unit on the inner wing is just a filter housing with a primer in the top of it? I could bypass it (in theory) completely if the fuel line went direct to the pump?
I wouldn't do that obviously, just trying to understand the setup.
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Re: Air in fuel on The Estate?

Post by Kitch »

Mothman wrote:I am currently running Mollie about using a fuel can in the bulkhead as she has a fractured fuel pipe. I found exactly where the leak was by blowing down the pipe having disconnected it from the pump and saw where fuel was leaking.Now just have to replace the fuel lines. I wonder if you have a pipe thats corroded through?

Andy
Possibly a corroded pipe. Wasn't sure what sort of an impact a leak in the pipe before the filter would have. I guess if it's using the fuel quicker than it's filling up the bowl (due to the leak....even if it's only caused a loss of vacuum) then it will eventually dry up like it seems to be.
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Re: Air in fuel on The Estate?

Post by Mothman »

A busted fuel pipe might be causing drain back from the system.
Certainly with Mollie, no fuel is getting through. Certainly sounds like air in the system somewhere to me.
Sophie was like that when i first got her, ran really rough and it was the diaphram on the primer that had failed. You can still get the entire original BX Purflux system if you know where but its costly. Once changed she ran like a dream and still does. Done the same for Gloria too.

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Re: Air in fuel on The Estate?

Post by rutter123 »

Kitch wrote:
rutter123 wrote:bypass the cav type fuel filter mounted on the inner wing with a simple inline filter, or fit a fuel line supply straight from a can to the pump and a fuel line from the pump return to another container, this will eliminate any fuel supply probs or blocked lines etc etc when i got my tzd i had a similar prob but managed to keep it running this way to get it on the trailer, this was on on a cav/lucas pump.
later i drained the tank and fitted new fuel lines from front to rear, binned the cav fuel filter and fitted 2 inline filters in place of this, has been like this for 70k now with no further probs, changing the inline filters every 5k service. hope your probs are as easy to cure.
That's a good idea! Will help me pinpoint the problem at any rate.

So that unit on the inner wing is just a filter housing with a primer in the top of it? I could bypass it (in theory) completely if the fuel line went direct to the pump?
I wouldn't do that obviously, just trying to understand the setup.
yes in theory it is just an inline filter with a primer pump, even when bypassing it use an inline filter in the supply line this will catch any crap before it enters the pump, its also not uncommon for the old steel fuel lines to corrode quite badly, would recommend new fuel lines f to r you can use copper or cupra nickel as a replacement 6mm bore pipe, you could even run some diesel purge thru at the same time this will clean all your injectors and associated parts.
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Re: Air in fuel on The Estate?

Post by BX Bandit »

Rubber components absorb diesel fuel and their additives. If it's stood still for 3 years then there (could) will be numerous points where rubber has shrunk (and cracked) through lack of use and letting air in. This will not only give the more obvious poor running with the 'air-in-fuel' scenario but you'll get reduced 'suction' from the pump as well.
Replace or secure all rubber to metal piping (preferably replace) including the leak off pipes. Also be aware that diesel 'goes off'. I'm not familiar how exactly, but I 'think' (happy to be proved wrong) that it's volatility reduces with age (like petrol) or it becomes more viscous . Give it a fresh fuel filter and prime as much fuel through as you can be arsed with. You'll need a good purge of diesel through the system to get fresh diesel up to the injectors.
Check/replace the air filter too.
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Re: Air in fuel on The Estate?

Post by Kitch »

All good stuff guys, thanks. I'll hopefully get it running long enough tomorrow to get it up on the ramp and have a poke around. For the cost and ease of it all I might just as well replace all the fuel lines I guess! Don't fancy splashing out on a new primer unit, so if that's shagged I'll do as rutter suggests and get some cheapo inline jobbies, and fabricate a bleed valve thing into it all somewhere with one of those universal primer bulbs.
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Re: Air in fuel on The Estate?

Post by docchevron »

shiny new primer bulbs are about £16 on the bay opf plenty mate
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Re: Air in fuel on The Estate?

Post by citronut »

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Re: Air in fuel on The Estate?

Post by KevR »

BX Bandit wrote:Also be aware that diesel 'goes off'. I'm not familiar how exactly, but I 'think' (happy to be proved wrong) that it's volatility reduces with age (like petrol) or it becomes more viscous .
Don't think so - it's not really volatile in the first place. It's more oily than that. Worst problem if it's been sitting is a usually a build-up of gunge caused by micro-organisms that live in the fuel. Can cause a revolting jelly-like mass which causes all sorts of problems.
Agreed about the rubber lines though - modern petrol and diesel contains far more ethanol than older formulations and that can attack older fuel lines. They need to be replaced using hose rated to SAEJ30 R9.

If the solid pipes need replacing, I think genuine ones are still available and not too pricey, but I'd replace them with copper heating pipe. From memory the feed is 10mm od and the return is 8mm.
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Re: Air in fuel on The Estate?

Post by BX Bandit »

KevR wrote:
BX Bandit wrote:Also be aware that diesel 'goes off'. I'm not familiar how exactly, but I 'think' (happy to be proved wrong) that it's volatility reduces with age (like petrol) or it becomes more viscous .
Don't think so - it's not really volatile in the first place. It's more oily than that. Worst problem if it's been sitting is a usually a build-up of gunge caused by micro-organisms that live in the fuel. Can cause a revolting jelly-like mass which causes all sorts of problems.
Agreed about the rubber lines though - modern petrol and diesel contains far more ethanol than older formulations and that can attack older fuel lines. They need to be replaced using hose rated to SAEJ30 R9.

If the solid pipes need replacing, I think genuine ones are still available and not too pricey, but I'd replace them with copper heating pipe. From memory the feed is 10mm od and the return is 8mm.
Yes that's the aspect I was referring to - the micro-organisms, old diesel smells foul (but possibly it's combustability (rather than it's volatility as you say) is affected?)). More viscous though which will affect pump and injector operation.

Cheapest option Kitch is to replace the fuel pipes with rubber hose. You have fewer joints and obviously don't need to bend/pre-form a copper pipe. A quick easy and cheap job
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