Bio temperature, viscosity and lubrication.

[Tony]

Incidentally I too changed a load of stuff with the first pump trying to fix it (timing chain, hydraulic tensioners, glow plugs, wiring to plugs, injectors and more, all to no avail).  The missing/clatter with the old pump at cold idle was random, not every time one cylinder fired.  It would go purrrrrr-clack-pur-clack-puuuuuuuuurrrrrrr-clack if you see what I mean.  Each "clack" would give a puff of unburnt fuel from the exhaust.  My new pump doesn't clatter much at all at cold idle, the clatter comes from driving it while still cold.

I'm convinced it's a timing thing that would go away if I adjusted the pump timing, however I'm reluctant to do so because a) it runs fine when hot and b) I'd rather find out what causes it in the first place

[Head Womble]

Julian, if you do wont to set / check the timing don't forget about the timing kit on VOD,
I think Jules still has it at the mo.

[Julian]

The more I think about this the more I recon it's the pump.  It's just strange that the symptom manifested it's self on two pumps.  Wondering how big a job rebuilding one is and what the parts cost ... or getting a man to do it.

Mark, I don't think you can use a clock on a Disco.  It's just a pin in the fly wheel (or in my case an old drill bit in a drilled out bolt), a rod in the IP (or in my case an old, turned down tommy bar) and a mark on the camshaft pulley, that's right or wrong by one tooth.  The IP pulley does have additional, small adjustment, but attempts at changing that to date have been less than successful.

The engine ticks over as sweet as a nut, starts OK and runs well hot and cold, save for this "missing" issue ... if it were timing it wouldn't behave as well as it does?

[Tony]

The more I think about this the more I recon it's the pump.  It's just strange that the symptom manifested it's self on two pumps.  Wondering how big a job rebuilding one is and what the parts cost ... or getting a man to do it.

Mark, I don't think you can use a clock on a Disco.  It's just a pin in the fly wheel (or in my case an old drill bit in a drilled out bolt), a rod in the IP (or in my case an old, turned down tommy bar) and a mark on the camshaft pulley, that's right or wrong by one tooth.  The IP pulley does have additional, small adjustment, but attempts at changing that to date have been less than successful.

The engine ticks over as sweet as a nut, starts OK and runs well hot and cold, save for this "missing" issue ... if it were timing it wouldn't behave as well as it does?

If you can be sure of #1 piston TDC position you should be able to time it using a gauge on the high pressure plunger, if there is a figure for lift at TDC for your engine (which there must be somewhere!)

When it misses, is there any noise associated with this?  Missing with a clatter if too far advanced, missing with silence is too far retarded.  Or, your pump is knackered...

A full pump rebuild would cost about £400 depending on what needs replacing, that's assuming you do the pump removal and refitting yourself.

[julesandtash]

Diesel bob quoted me £250+vat for a full 300Tdi pump rebuild including return postage. I never took him up on the offer though as, except for having a new front seal fitted, the pump is still going strong.

I dont really know what else to suggest, you have tried everything really. By the random nature of it I suspect it must be the pump but what is happening I have no idea.

[Julian]

Well, if you don't know, then no one will know ... I'm off to look at Jee,  Jeeeee,  Je,  American cars!

[julesandtash]

You could sneak up to Essex and pull that 2.8HGV engine out of JulianFs 101, he isn't using it 

[Julian]

Tempting!

[julianf]

You could sneak up to Essex and pull that 2.8HGV engine out of JulianFs 101, he isn't using it 

hey, less of that!

its a camper van.  as in holidays.  as in those things you have when you have not got a million and one other things to do.

one day i hope to have them again!