EGR and Cold start help Xantia 1.9TD 1998(mk1)

[admiral51]

Hi all

Im aware that the EGR has been well covered previously on its detrimental effects but have not yet read/seen an idiots guide to removal and cleaning
I am suffering what i can only describe as hunting/over running at idle with the aforementioned car.It doesnt show on the rev counter but its just that feeling of the engine not being happy at idle its difficult to describe
Im pointing the finger of blame at the EGR Valve (seems fair ) so would like to take it off the car and clean it before disconnecting it as i assume that the inlet manifold will also be a bit gunked
Is this a relatively easy job to do or are there some major pitfalls i need to be aware of
Assume that this is the EGR


Also would like some feedback on this particular object


Im assuming its to do with the cold start mechanism as it seems to go to the sensor on the bulkhead next to the EGR sensor
The pipe on the end is split as can be seen in the photo is it just a simple case of replacing said pipe as the car is beginning to be a sluggish on start up. starts fine no problems there just needs a little bit more time to settle down

Thanks in advance

Colin

[red_dwarfers]

Also would like some feedback on this particular object

That object is indeed to do with the cold start mechanism. There is suction in the pipe when the car is on warm idle and no suction when the car is on cold idle. That cable and plunger bit is fully relaxed in your picture setting the pump to its default setting of cold idle (around 1050rpm). Its not really worth fixing it as the only real advantage at warm idle (around 850rpm) is that the engine sounds smoother.

[citroenxm]

The EGR valve is bolted to the exhaust manifold, and I doubt with the hotish tempertures the manifo0ld gets to you'll get it off...

Ive just dumped an EGR valve off a P reg Xantia TD, by means of swapping the whole turbo unit... I had driven the car before the change and it was quite "dead" to say the least, but now, it flies along! amazing difference...

Bit of turbo spin up smoke, but thats about it!

If you managed to get the EGR off, you'd ALSO need to change or block off the inlet manifold as its connected to that... I happen to have a 1994 inlet with it already blocked off...

Paul

[KP]

If your running on veg or thick-ish bio then its best to keep the idle a bit higher, specially when the weather gets cold.

I always found when running 100% that pouring warm water over the injector pump and the injector pipes before cranking in the morning and then priming the primer bulb and it would always start within a second or two after a 2 runs or 3 on a very cold day, of the glowplugs...

[Xaccers]

I always found when running 100% that pouring warm water over the injector pump and the injector pipes before cranking in the morning and then priming the primer bulb and it would always start within a second or two after a 2 runs or 3 on a very cold day, of the glowplugs...

Is that with 100% WVO?
Even when it's been snowing/icy I've never had to do more than two runs of the plugs, unless they've needed replacing so I'm intreagued

[MikeT]

Do you suffer poor idle when cold, hot or both?

The vacuum hose is fitted to the fast-idle as you've identified. If it's working and is leaking, that would cause poor idle when warm.

[citroenxm]

Are you sure Mike? Ive had a Xantia that this was never connected, only by misfortune, and there was never an issue with bad idleing..

All those valves have replaced are the Wax type fast idle advance from the older thermostat housings.. Ive removed the EGR from this P plate, and not got the valves connected and it runs a dream, and idles perfectly...

Paul

[KP]

On one Xantia i had the mechanism was siezed in the fast idle position so this is maybe why yours when disconnected was ok, and the vacum hose plugged somewhere else maybe?

[MikeT]

Are you sure Mike?

Yes Paul, let me explain:

Without intervention, the bosch pump will run at the fast idle setting.

Once the ECU considers fast idle is no longer needed (ie engine temperature rising), it energises the solenoid/electrovalve. This in turn allows the vacuum to pass onto the "flying saucer" which then pulls on the cable disabling the fast idle and allowing the normal idle to take over.

So my theory is; with the vacuum hose in that condition, I wonder if it's possible it's causing a pulsing vacuum, maybe due to vibration, maybe due to suction or both, which might create an irregular idle but it's only a guess.

[admiral51]

Thanks for all the replies gents

Do you suffer poor idle when cold, hot or both?

Its usually only when warm/hot.the strange thing is that it appears from the rev counter to actually drop the revs when warmed up but i still get the feeling that the engine is trying to rev a little nothing noticeable on the rev counter just dont feel right

I had driven the car before the change and it was quite "dead "

happen to have a 1994 inlet with it already blocked off

That is my thinking it goes ok just not what i really think it should

The EGR valve is bolted to the exhaust manifold, and I doubt with the hotish tempertures the manifo0ld gets to you'll get it off...

I was hopeing to be able to remove it and the manifolds to give them a good clean...seems its not that simple

Are we talking the possable exchange of beer tokens

Cheers

Colin

Sorry for the delayed replies been getting the VSX ready for MOT tomorrow(wed 15th)

[KP]

I always found when running 100% that pouring warm water over the injector pump and the injector pipes before cranking in the morning and then priming the primer bulb and it would always start within a second or two after a 2 runs or 3 on a very cold day, of the glowplugs...

Is that with 100% WVO?
Even when it's been snowing/icy I've never had to do more than two runs of the plugs, unless they've needed replacing so I'm intreagued

Yip, on one such day the temp reading on the dash was saying -8 and it was never too far wrong to be honest

The glowplugs seemed fine as when it was a tiny bit warmer, ie above 5' outside it would work with just one cycle of the plugs and no warm water...

[MikeT]

Thanks for all the replies gents

Do you suffer poor idle when cold, hot or both?

Its usually only when warm/hot.the strange thing is that it appears from the rev counter to actually drop the revs when warmed up but i still get the feeling that the engine is trying to rev a little nothing noticeable on the rev counter just dont feel right

Then surely it's worth replacing the fast idle vacuum pipe? It just might cure the idle and is a darn sight easier than EGR cleaning.

I can't see how a dirty EGR would cause anything other than a lack of power. It's the fuel that alters revs. But if you're insistant, I'd be happy to lend a hand.