Anything Else Before I Swap the Pump

[Pug_XUD_KeenAmateur]

In a line... is there anything more to check before I condemn the fuel pump and fit a replacement one?


Details.....
Car running normally and in use (town & motorway) with no issue
Car started immediately as normal and ran fine for 30 seconds
Car cut out out suddenly while I selected some different music, not a cough, a splutter or any rough running
Refused to restart
Checked cam belt: that’s fine (and only a few months old)
Ran a feed direct from the battery to the Stop Solenoid: nothing
Undid all four injectors and checked for fuel delivery: none
Primed it and cranked it for quite a while, a couple of times, thinking possibly fuel's ran back to the tank (its never done it yet, but there's always a first time): still nothing
Listened for a click at the stop solenoid while having an assistant switch on Ignition: none
Visually examined the two wires to the stop solenoid: they're fine
Removed plunger from stop solenoid
Noted plenty of fuel in the housing the stop solenoid screws into, mopping it out to see the thread better having briefly struggled to refit it minus its 'spring' (turned out I'd omitted to ‘angle it’ a bit)
Tried again: still nothing
Replaced stop solenoid with a known good one, noting that the fuel had re-appeared in the housing beneath it to obscure the thread, as before: still nothing
Exhausted battery, put it on charge and gave up for the moment.
I do have a known good replacement pump, but a sudden & total failure of a pump that was fine to that moment doesn't 'ring true' somehow.
Is there anything else to check before I go that route?
Your assistance is greatly appreciated as ever.

Am I pleased? Am I heck. Not only has the car only been on the road for 2 days, covering 200-ish trouble free miles in the course of them, following 3 weeks of welding to the NS Cill

....but this also comes on the back of daughter’s Euro Car Parts RTX Alternator (Pug 106D) failing yesterday after just 1 month and approx 700 miles. ECP refunded it and supplied a slightly better, slightly more expensive one (at extra charge) but I still had the aggravation of fitting it, which is a bit of a pig of a job in this application, albeit a lot quicker & easier second time than it was the first.

Cars, Grrrr!!

NB 1: pump is a Lego Lucas Rotodiesel, on a 1995, 245,000mile, 1.9 na Pug 405D
NB 2: recent filling station visit so plenty of juice
NB 3: can't be an immobiliser issue, this one doesn't have the 4 digit security keypad and corresponding 'anti theft' cover thingy on the top of the pump

Merry Christmas !

[CitroJim]

That’s a bit of a to happen today

Last check is to bypass the stop solenoid completely by removing the plunger and replacing the solenoid minus the plunger... It'll now be effectively always open...

When you prime (with stop solenoid bypassed) can you see fuel flowing in the return line back to the tank?

Is the emergency stop lever properly 'home' in the run position?

If both of that is OK then it's something internal to the pump.

My assessment would be a gummed-up metering valve/pin... I've known it happen in the past where it was stuck such that the engine would slowly idle and not rev.

The metering valve/pin can be got at without removing the pump; slip off the top cover and it's on the end of the governor (throttle) lever assembly - just south of the spring assembly.

I'd check that before taking the pump off... Not much else really to fail like that in a Lucas DPC and completely stop it...

I have a diagram somewhere if that will help..

[CitroJim]

Here's a diagram showing the metering pin (item 7)..



It'll be obvious how to get to it when the lid is off...

Work in very clean conditions, you want not the tiniest spot of muck to get in the pump whilst you work on it...

[Pug_XUD_KeenAmateur]

That’s a bit of a to happen today

Thanks Jim, for the advice and the diagram.

Isn't it it just!! The degree of my unhappiness is hard to accurately communicate in words other than those with four letters. A phrase with the word 'scrapyard' in it was used also. Sad to say the old girl has been nothing but trouble this year.

I've already tried the bypass on the Stop Solenoid.

I haven't had the return line off so I've no idea about that one. Would fuel rushing out of the return mean the pump is ok? When I prime I get to about 3 good squeezes then it goes hard. I'll be removing the return line and running it into a can next attempt....

I'll also be attempting to get fuel through from a jerry can, with the lengthy and expensive mis-diagnosis shenanigans of recent history in mind, which ultimately turned out to be a chaffed fuel hose.

I'm not aware of an emergency stop lever, and my Haynes BoL's* don't mention one either. I do have an inertia switch; however both seem unlikely culprits as the car was standing still and just ticking over with my right foot nowhere near the go faster pedal (which works in a fairly modest manner appropriate to being normally aspirated, lol)

Mine won't start at all by the way, which is no surprise seeing as there's absolutely zip at any of the four injectors. Idling but refusing to rev is also not good of course, but would be an improvement!

Is there anything to cross check re suitability prior to fitting the pump? I know its fine having started it and ran it for 10mins before I stripped it; but I just want to be cautious as it was a Cit ZX, of the same vintage. I was sad about it at first, but then I realised how rotten it was and noted that the coolant was brown, oily brown; before I stripped it.

*Pug 405 Diesel and Pug/Talbot Diesel Engine BoL's

[Peter.N.]

Those pumps are usually very reliable but it seems you have tried everything to locate the problem except the last one you mentioned, supplying fuel to the pump from a desperate container, that's certainly worth a try as you could have an obstruction in the fuel tank, piping or filter, although if you can get a fair quantity of fuel by pumping the primer that would seem to indicate that the feed is OK.

I suppose your cam belt hasn't broken, a quick test would be t squirt some easy start into the air intake and see if it runs.

Peter

[CitroJim]

Here's the stop lever:



The other possibility is that the distributor head has seized and in consequence broken (deliberately - to protect the cambelt/engine) the pump drive shaft... Have you ever ran this engine on veg at all as veg will surely kill it...

One more remote possibility - a sheared woodruff key allowing the pump sprocket to rotate without actually driving the pump or causing timing to be way off...

Any Lucas DPC originally fitted to a 1.9 NA XUD will be fine. You might even get away with a DPC fitted to a 1.8 NA XUD too...

[Pug_XUD_KeenAmateur]

Thank you Peter and thanks again Jim, it looks like you've gone to quite a bit of trouble there with the photo of the pump.

'er indoors has decreed that I'm not to do anything on it today on account of it being Christmas Day, so I'm going to stay well away from the car with the sledgehammer and having armed myself with a print out of this; I shall check out the points raised Boxing Day or soon after.

Oh, and no, I've never run it on anything other than pump diesel. I don't approve of this at all having experienced in my previous 405 the performance available from a replacement engine off a scrapper that I know had been run on veg.... then having gone to all the trouble to change the engine, I enjoyed a breakdown in North Yorkshire, not more than a month later, some 200 miles from home.

Its all well & good to save 10pence a litre by using Veg in a Lucas pump, if you feel the expensive consequences of doing so represent good sense.

[CitroJim]

No trouble at all for a fellow XUD driver

Have a lovely Christmas Day and may Boxing Day see yours back running sweetly again

[ekjdm14]

Snapped shaft was my first thought too with a sudden & total failure. Less likely as it's not been run on cooking oil though. You did mention a recent fill-up so I wonder if perhaps you got contaminated fuel that's caused a pump issue?

Anyhow, merry Christmas to you & everyone else on the forums. The missus is calling now to help with dinner and set up the cats' present (some huge scratching post/treehouse thing lol).

[CitroJim]

You did mention a recent fill-up so I wonder if perhaps you got contaminated fuel that's caused a pump issue?

The design of the Lucas DPC distributor head makes it very critical of lubrication and it does not take much to destroy it...

In the early days of ULSD (Ultra-Low Sulphur Diesel) many DPC pumps were 'lost' as the sulphur is a good pump lubricant. Removing the sulphur reduced substantially the lubricity of the fuel and the fuel companies had to work quick to restore the same levels and qualities of lubricity found in pre-ULSD diesel...

This is the fundamental reason why a Lucas pump cannot run veg.

Bosch pumps very rarely suffer this sort of failure as they use an entirely different type of distributor.

[Gibbo2286]

Just to say you're not alone with your Christmas problems, my central heating boiler died and the local boiler fixer misdiagnosed the fault fitted £115 part and it still won't go, another £45 part and it still won't go
Thank goodness for the gas fire and electric fan.
Still at least we haven't got problems such as the Russian military choir's families today.

[Gibbo2286]

I just had a thought about your fuelling problem, you've been welding, have you by any chance been close to the plastic fuel pipes?
A softened plastic pipe might be closing up, sucked flat when primed and blocking the fuel flow.

[Peter.N.]

We have oil, calor gas, electricity and a multi fuel stove, so what failed last week just after I came out of hospital and wasn't allowed to lift anything - our water supply, the pump had failed but with a bit of help from my wife fortunately I managed to fix it.

Peter

[CitroJim]

Gibbo, sorry to hear about your boiler Just the time of the year you don't want anything like that happening...

Good point about fuel hoses

[Pug_XUD_KeenAmateur]

Thanks for all the messages guys raising some valid points; all of which I’ll be referring to in my further testing, both visually and with a temporary supply.

Also nice to be reminded that actually, others have got issues too.

Its probably gonna be Weds before I get the spanners out now, by which time I’m sure my mood will have lifted further. I shall take some appropriate photos and post them to the usual folder as well as putting a further post here to keep everyone updated.

Merry Christmas likewise to you all.