Rough starting diesel

In message , Tom writes

Typical behaviour when the glowplugs have gone.

The message from tommie_de snipped-for-privacy@hotmail.com (Tom) contains these words:

Very likely glowplugs. They're easy to test - just check for a handful of ohms to earth. They're almost always either very nearly dead short (working) or open circuit (dead).

Could be glowplugs, although I wouldn't expect all of them to go at once. Alternatively an air leak in the fuel supply to the pump, usually where the rubber hose goes down by the engine to the metal pipe running back to the tank. A couple minutes running gets rid of the air then the air leak allows the fuel to drain back to the tank overnight. Dave

It sounds very much like the glowplugs. It's quite a common thing for people to notice in October as it starts getting cooler.

The message from "DervMan" contains these words:

Sweepstakes on the first iced up carburettor of the season, anyone?

I'll take 12th December.

I'll be aggressive: 17 November. :)

In message , Guy King writes

What's a carburettor? ;)

31 Dec. does it cure pinking? ;)

Glowplugs.

Is this the first of the winter?

It'll be carb-icing next!

Pete.

The message from Dave contains these words:

Most engines will start with little hesitation on three plugs but struggle badly on two - so it's only had to have one plug fail to make a dramatic change. He says he's getting grey smoke - so there's fuel getting there, so it unlikely to be caused by fuel starvation.

Yes. I was happy to let my Mondeo run with three plugs during the summer of

1998 because it didn't make any difference. Another failed between the service in early September and the first frost in October :) so I had the set replaced.

I take your point about the plugs, but what sometimes happens is the fuel in the line is allowed back into the tank as air leaks into the pipe. The engine then sucks up a mixture of fuel and air until all the air is gone and the pipe is full of fuel again. The pump cannot build up an adequate (very high) pressure if there is air in it, so this mixture is not atomised properly through the injectors. You get poor starting/ running (with smoke out the exhaust) until the amount of air is low enough not to make any difference and the fuel is being properly atomised again. This gets worse as the leak worsens until it won't start at all, but only after a long enough wait for the fuel to leak back - so it's easy for a garage to try a couple of things (like a new set of injectors because 'they're not spraying properly') then say "Look, we've fixed it - it starts ok now!" A few hours later of course you're back to square one. It's easy to check so why not try it? Dave

Snort

-- Malc

Changed the glowplugs today, but no improvement. I'ts probably the glowplug relay since the preheat light on the dash doesn't come on. (Should have thought of that before but thought the bulb was broken because the car used to start without dash light.) When i feed the plugs directly from the battery the car does start. Anyone knows if all citroen/peugeot diesels use the same relay (scrap yard)? A new one for my XM is rather costly.

Thanks

Tom

The message from tommie_de snipped-for-privacy@hotmail.com (Tom) contains these words:

You might have told us earlier!

Some glowplug timers take a reading from the temperature sender on the block - is the dashboard gauge showing correctly?

One of my plugs failed to a dead short taking the fuse with it, thus disabling all the plugs, but the plug light still came on!

Tom

One of my plugs failed to a dead short taking the fuse with it, thus disabling all the plugs, but the plug light still came on!

Possibly try testing your old plugs on a multi-meter and checking the fuse

There was an 80A Fuse in the engine bay fuse box for them.

This was on a corsa btw.

Tom

Try this:

Hook up a small bulb direct to the Glowplug feed.

Two indications are now given. 1) Existing light tells you when the plugs are upto temp.2) Newly installed light tells you if power is reaching the plugs and later will tell, you if the relay has stuck on. The latter will eventually burn out the pluga.

R4

Took me a little bit of reading back posts till I got it.

Then I wished I hadn't....:-)