Priming A 205 Diesel

[steve@cornwall 100]

Got a problem with a non running 1.8 non turbo. 1991 car with Lucas pump.It has a non standard looking clear pipe from the filter to the pump (the cable tie at one end is definitely non standard). Should there be a priming bulb in this line to prime the pump?

The fuel is in the filter, but not travelling down the line to the pump.

When cranking there was initially diesel being forced at what seemed low pressure to the injectors with the supply union cracked, but this has obviously diminished now with repeated cranking.

Car has sat for a couple of years, was a reliable starter before that and I have added a small amount of fresh diesel, the gauge reads around a quarter tank.

As you can probably tell I'm a complete.diesel virgin so all help gratefully received

[welshpug 1,661]

the earlier fuel filter arrangement has a remote metal canister, on the top of this is a priming button, however they are notorious for not working.

 

later systems with the paper element filter in a plastic housing has an inline priming bulb which incorporates a one way valve.

 

you can pick up these bulbs and retrofit them, not that expensive from a dealer even.

the clear line may well be original, but does need more than just a cable tie to be fuel/air tight

[steve@cornwall 100]

Thanks Mei

It is the later type with the paper element filter but has no priming bulb so I'll pick one up and some proper fuel line clips too, the top has a weak looking jubilee clip and I understand they don't like leaks at all. It did actually fire a few times so I am hopeful.

[steve@cornwall 100]

Just for some clarification please

There is no lift pump ?

As the tank is lower than the pump so cannot be gravity fed I assume it operates by permanent syphon?

If working correctly the fuel from the pump to the injector should be supplied at extremely high pressure?

Apart from the pump itself requiring priming are there any common reasons for non starting after a period of non use?

Parts that may fail?

 

Apologies for the barrage of questions but my knowledge of diesel engines is not much more than they rattle when they run!

 

I'm also assuming that garages don't use the "pumping the bulb while bleeding pump" method . so is there another sky work around? Or does this involve expensive bespoke pump set ups? (An if so could these be hired? The bulb I bought at halfords seems to be more of a symphony starter and not air tight at any pressure.

Edited May 25, 2016 by steve@cornwall

[welshpug 1,661]

no lift pump on the mechanically injected pug engines no, the pump aucks the fuel up itself.

 

priming with the bulb is used by everyone, an alternative way if its quite a dry system is to feed it easy start or brake cleaner in sparing quantities to get the engine spinning over fast enough to push the air out.

 

another is to crack off the injector unions whilst cranking till they squirt a defent amount then nip them back up.

 

no black magic to these things, wonderfully simple really.

[steve@cornwall 100]

It has run briefly with a remote fuel supply, but some more daft questions.

 

I opened th vent valve at the top of the pump an the level was somewhat low. Pumping with the bulb (already firm) did not raise it, so I poured in a little diesel. Pushing the bulb overflowed it very slightly but no air bubbles.I note from my downloaded Lucas pdf that there is an internal filter, is this serviceable? cos I can't find it.

 

Having nothing to test (running short on time an not even a bulb to hand) I ran a permanent supply to the pump solenoid, it cranked much much faster and cracking an injector union showed much more pressure and no air so I tightened it and tried again. and it caught.....Eureka ! But only one time. Anyway, I've read that these diesels require a heavy current to start reliably and as it has no battery I'm using jump leads from my gti while it's running, possibly not enough? I also need to replace the diesels alternator.....it started smoking...lol

Edited May 28, 2016 by steve@cornwall

[steve@cornwall 100]

Well I got it going. Bought a shiny new battery , primed from a can, filled the pump with diesel via the vent at top and away she went. However, as soon as I move the bulb it let air into the supply and died.

Primed by sucking one the pipe! But would not lift diesel from the tank (nearly half a tank in it now) so removed the filter , repeated the above and she now starts great. A result.

[pugdamo 111 2 Cars]

Knew it would run, they are such good motors. Your now all up to speed on the complexity of the xud lol. You can start fitting the trims now.

[steve@cornwall 100]

Few jobs before that unfortunately, windows,locks,CLEAN and some blow-over paintwork. Will find out later if there's any air leaks to drain down again certainly hope not I'm not partial to the taste of diesel!

[pug_ham 244 3 Cars]

Steve, how old are the main flexi pipes from the metal pipes on the bulkhead?

 

They perished through on my old STDT & caused issues similar to yours.

 

Replaced the pipes & everything was fine from then on.

 

g

[steve@cornwall 100]

Graham, I would imagine they are the original flexis,so I'll certainly bear that in mind if I get problems when I fit a new filter. Also the underside of the car is quite orange, it's lived by the sea all its life so the main fuel pipes also may be pinholes although there's no sign of leakage.

On the plus side it started very readily today,barely cranking before coming to life,a few stutters and understandably a little smokey.On the whole a lot quieter and smoother than I expected.

I have seen a cheap,facet type fuel pump on line, so if the fuel can be pulled through it when not pumping I may try one of these as a makeshift lift pump for priming etc

[Anthony 1,003]

You shouldn't need a lift pump. They're really sensitive to air leaks though and the tiniest leak - even if it is so small not to leak diesel - will cause it to run like a bag of spanners if it runs at all.

 

As Graham says, check all the fuel lines, the primer, the filter/housing and the pump itself for any evidence of a leak or perishing. Once all that's sorted, check/replace the glow plugs with decent (Bosch) ones and it should start on the button with no/minimal chugging and smoke

[Paul_13 212 1 Cars]

I still remember you driving my diesel back after we finished building the gti

 

The primer pretty much died and nearly didn't get the car home