Citroen XM Forum

Jaap, the leakoff pipes are the little black ones daisy-chained between each injector and then going off to tee into the fuel return by the pump. Each injector has two little spigots either side of the main fuel inlet union that look like little ears. The end injector has a blanking cap over one of the little ears and these are terrible for splitting. I never used blanking caps but used a piece of pipe bent double and secured with a couple of cable ties. The leakoff pipes ferry spilt fuel that leaks past the injector needles safely away..

I used to find that glowplugs were needed always, hot or cold, summer or winter. It's a design feature of the Indirect injection system used on the XUD engine that preheating is always required to heat the air in the pre-chamber to ignition temperature as the main compression provided by the piston won't do it.

An XUD with four duff glowplugs is incredibly hard to start as this video shows:

Poor 405

In fact it's remarkable it started at all and this video shows how important post-heating is too. That's where the glowplugs stay on for several minutes after the engine starts..

[youtube]4xs4TBHWq9k[/youtube]

Russ, I believe the big problem with the filter head is the priming diaphragm - the bit behind the priming button... I've not had a lot of experience of them unfortunately so can say no more than that.

So if the filter primer head is at fault. What is the best cause of action?
By pass it with a priming bulb and smaller filter, or try and get a new canister type. Are just the heads available? Problem is where on earth do you go to get a new one?

I have read it is the diaphragm that goes, not necessarily the rubber o ring Jim....Many thanks for confirming.

Mine was definitely not doing that like the 405. So it isn't the glow plugs!

Cor smokey!

There used to be repair kits for the primer Russ but I believe they're now hard to get hold of. Doubtless someone will soon be along to say the best way of resolving this issue - perhaps with a different filter and a grenade primer...

It definitely sounds like air leaking in, try running it from a can of diesel straight to the pump.

If it's the filter-head, buy a new, better unit.

Series 1 XM glowplugs don't have post heating.

Thanks Jim, I read your mail about 6 times with the laptop on top of the engine Hmm, those small black pipes are hardly visible. I take it you have to take the top alloy manifold off if you need to go there?

The vid.link did not work with me, will try again. I don't have blanking caps anywhere, all injectors with pipes, look identical to me and dry thankfully. Injectors normally don't need maintenance on the Diesel I hope. So we keep heating the air while starting always ( I haven't done that but having said that: I drive to work in one go and back as well. Don't use the Diesel for shopping yet.
Russ, do you want me to find a primer head? I wonder what could go wrong on it. What's that diaphragm made off?

Yes, the top part of the manifold needs to come off to get at the leakoff pipes Jaap... As long as all looks dry around the injectors and she starts well then no worries at all, they'll be OK... The time to really look at them is when starting after an overnight rest is hard. Look at the injector nearest the bellhousing to see the blanking plug - unless it's been replaced with a bit of pipe bent over upon itself..

I'm surprised there was no post-heating on the S1 XM Will. Did it only come in with the EPIC then? The 1.9TD Xantia had it right from the off in 1993 with the fully mechanical pump so I rather thought the XM would have had likewise...

Post-heating on a TD makes a difference to the cold running and smoke production and is normally in effect until the coolant is up to 60 degrees or the throttle is opened more than a third.

2.1 don't smoke after start.

Dieselman wrote:2.1 don't smoke after start.

Shows it's a vastly superior engine to the 1.9TD in many ways. The 2.1 is the best IDI diesel PSA ever made in my opinion but then
I've never sampled the 2.5...

EDIT: Just noticed I'm on 2088 posts - the exact capacity of a 2.1TD, the subject of my 2088th post

LOL...