Xantia TD Hot Start Woes

nexarius · Post by **nexarius** » 18 Jun 2007, 22:08

My dad has a 1997 Xantia TD.

He has had it from about 100k and it has now done 180k.

Ever since he bought it, it has been reluctant to start when warm, often needing up to 10 seconds of turning over before it would fire. Cold starting is fine.

More recently, the problem has gradually got worse, to the point that it often completely refuses to start.

The AA have blamed the battery terminals and the battery, and we have replaced both. Doing this made things better temporarily.

It only happens when the engine is very hot, ie very long journies. Trying to restart the car after stopping it for more than about a minute is impossible.

Rather strangely, if you push start it, or start it with jump leads, it starts up quickly. This leads me to rule out fuel delivery.

When it is hot, it turns over quite slowly. The battery is brand new and has 14.5v across it when the engine is running. It will crank over moderately quickly for ages but the engine just doesn't catch.

Anyone got any ideas? He has got a newer car now, but it would be nice to get this one working so we can at least *try* to sell it on!

So far on my list of ideas are: Injection pump, connections to starter, starter, timing

A car dealer we bought the replacement off said he'd seen this happening before with a car that had a hairline fracture in the head.

Any thoughts or advice would be much appreciated! Save a trusty old Xantia from heading to the scrap heap!

jeremy · Post by **jeremy** » 18 Jun 2007, 22:32

Hairline crack in head - would lead to loss of compression - would turn
quicker.

Starter - unlikely to run slower when hot - try tapping it (not hitting hard) - if it runs faster - brushes sticking.

General connections - set your meter to 20 volts or similar - and connect from the battery - terminal to the engine block and operate the starter. If the reading exceeds 0.25 volts the earth system is suspect. You can do the same with the + terminal and the power connection on the starter.

As its a Xantia it probably has a Bosch injection pump. What are the leakoff pipes like? What are the other pipes like. Roto-diesel pumps are not affected by leakoff pipe conditions but they will let air in on a Bosch pumped engine.

Does it pump out white 'smoke' when cranked but not starting? If the fuel system is pumping correctly I'd expect a considerable amount of diesel vapour to be pumped through the exhaust.

Post by **CitroJim** » 18 Jun 2007, 22:45

This all looks like a loss of compression when hot as Jeremy says, especially if quantities of white smoke pour out on starting attempts.

Another remote possibility is valve clearances closing up when hot although normally they're tightest when the engine is stone-cold.

Yet another remote one is worn rings/bores/pistons causing a loss of compression when very hot due to the oil becoming very thin. Cold, the oil would be thicker and thus would help provide good compression.

EGR Valve stuck open when hot? Could that cause it?

EDIT: Turning over slowly when hot may indicate the engine is very tight when very hot. Try turning it over with a socket and "T" bar on the crank pulley bolt when cold and again when very hot.

nexarius · Post by **nexarius** » 18 Jun 2007, 22:56

Hi Guys,

Wow, fast responses!

We tried the multimeter thing and when testing we were only dropping 0.1v across each connection.

When testing, of course, the engine wasn't hot enough to not start, and was turning over reasonably quickly. Would have started easily if we'd put the immobiliser code in.

I havn't checked the leakoff pipes because I don't know what they are, but having searched the forum a bit I think I know what I'm looking for.

There is no smoke emitted when it is turning over. There is a fairlly substantial amount of whitish smoke when it does eventually fire. This smoke would not normally be there if it had started right away.

Also, when looking in the engine when starting it, we can see a single 'puff' of smoke or something when it does fire. Just a single puff, from near the back of the engine.

Matt

TehAgent · Post by **TehAgent** » 19 Jun 2007, 01:06

puff of smoke from near the back of the engine? does it sound quite spitfirey? could be from the manifold to the exhaust. with a blow at the manifold you would also lose some back pressure, but doubt this would have an effect on starting

Also something you haven't stated, although its a new battery, what are the amps on it,

Leak off pipes are the small black plastic piping leading from the top of the injectors to each other in a chain, (mounted above the glow plugs) then one with a black plastic plug on the side.

mine is very similar, but seems to be something to do with the pre heat, when i start mine first thing in the morning, it now fires almost instantly, but when hot, i have to wait 4 seconds after the preheat light has gone out, before it will start, or it will just sit there turning over with out firing,

BrianM · Post by **BrianM** » 19 Jun 2007, 09:24

You're not making the mistake of thinking the car will start without preheating when hot ? In my 6 years of Xantia TD ownership no matter how hot the car is you still have to wait for the preheating to do its job for a quick start - otherwise it will turn for a (good) few seconds before starting.

Brian

97 Xantia TD

nexarius · Post by **nexarius** » 19 Jun 2007, 10:59

I don't know the CCA of the battery. The previous battery was fitted by the AA and was only about 3 years old when it was replaced to try and solve this problem.

After replacing it, the engine turned over much faster for a few weeks, but now its slow again.

I don't understand this, because the voltage across it is a good 14.5 when the car is running.

It's almost as though it loses voltage somewhere when its hot, or maybe its more difficult to turn over. It willl crank slowly at the same speed for ages before flattening the battery.

The glowplugs obviously work because it starts really easily from cold (like 1 second). It does run a little rough upon starting from cold, but then it has done 180k!

The puff of smoke is not an audible puff, and the sound of the running engine is no different to normal. Just a single puff of what looks like smoke, but could maybe be dust or something.

Thanks for the ideas!

nexarius · Post by **nexarius** » 19 Jun 2007, 11:57

The battery is rated at 600A.

Interesting Development:

I went out to the car to have a look at the leak-off pipes. In my general prodding about I squeezed the "grenade" priming thingy and it was completely soft. I squeezed it until it was firm, and continued with my prodding around.

After my prodding around, I felt it again, and it was completely soft again. I had not switched on the ignition or started the engine or anything.

Is this normal?

As for the leakoff pipes, I couldn't see any signs of leakage, but then since most of the front engine is uniformly covered in oil anyway, I'm not sure I'd have noticed!

TehAgent · Post by **TehAgent** » 19 Jun 2007, 12:03

best way to check you leak off pipes is by touch, diesel smells a lot different to oil, so just run your fingers along them from one end to the other, and smell any thing you suspect as diesel. (best done when engine is cold)

Your one way valve on the prima pump might be a bit dodgy if its going soft really quickly,

Post by **CitroJim** » 19 Jun 2007, 12:53

Thinking back, and it has onlly just come to me, my old Pug 405 TD never started as well hot as it did cold. Cold, it always started instantly but when hot it took a good few rotations and more the hotter it got.

It had the Bosch pump and speaking to a diesel specialist one day he said it was common now due to the much thinner diesel now in use. He may have a point. He said this problem would slowly get worse and its severity depended upon wear in the pump.

My Xantia TD, with the exact same pump, exhibits this to a very small extent. Two rotations when hot as apposed to one when cold. Interestingly, of all the XUDs with Lucas pumps I've had the pleasure to know, this has never been evident.

Although leakoff pipes are normally associated with cold-start problems, it is very equally fair that thay will cause this problem, especially with very hot (and thus thin) diesel.

The soft primer bulb may be a red herring. The Bosh pump is of "straight-through" construction to facilitate self-bleeding and any fuel pumped in via the primer bulb will very quickly go out through the fuel return line even with the stop solenoid de-energised. Unlike a Lucas pump, the stop solenoid works on the high-pressure side of the pump and not on the fuel inlet side as in the Lucas pump.

nexarius · Post by **nexarius** » 19 Jun 2007, 13:18

So is there a way I can distinguish the problem as being with the pump rather than the injectors (etc), without having to spend any money?

Post by **CitroJim** » 19 Jun 2007, 13:26

nexarius wrote:So is there a way I can distinguish the problem as being with the pump rather than the injectors (etc), without having to spend any money?

Well, the fact that there is no white smoke, or very little, (meaning little or no fuel is being injected) when attempting a start may suggest the pump is suspect but before condemming the pump, do replace the leak-off pipes (very cheap) and make a full check for air leaks.

If not already present, replace the final run of fuel feed line from the filter with a clear plastic pipe and observe this carefully. If you see big air bubbles during a start attempt, you then know you have an air leak between the tank, primer bulb, filter and the pump. Favourite spots for air leaks (once you've excluded the leak-off pipes) are the primer bulba nd the filter housing.

If all proves OK then it'll be the pump.

nexarius · Post by **nexarius** » 19 Jun 2007, 13:31

Thanks,

Why would a problem like an air leak appear only on hot starts, and why would turning the engine over faster make the problem disappear?

Post by **CitroJim** » 19 Jun 2007, 13:37

nexarius wrote:Why would a problem like an air leak appear only on hot starts, and why would turning the engine over faster make the problem disappear?

Expansion through heat can open up a split enoght to leak when hot but just seals when cold.

The diesel will be thin so will not seal nor pump as well but spinning the engine over a little faster will up the injection pressure just a little and thus make it start easier.

I know you have checked voltage drops etc. but have you tried another starter motor? Heat and starter motors don't go well together.

nexarius · Post by **nexarius** » 19 Jun 2007, 13:46

We are thinking about the starter being at fault, we're hopefully going to check the voltage drop across the earth strap when the engine is hot, just to make sure.

The problem is that since my dad has a newer car now (a shiny Vectra 2.0DTI), the Xantia is not getting any use whatsoever, making it rather hard to do tests on!

I'd rather like it for my own car (if we could fix it!) but the insurance for someone my age is a bit ridiculous. The cheapest I've found is just over £1600/year!