Fuel consumption?

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goldfinche
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Fuel consumption?

Post by goldfinche »

Hello all. I have a 1997. 2-1 TD Xantia. Just coming up to 100K miles. It usually takes 4 seconds of turning over to start from cold, when hot it starts instantly. It does not use any oil between services. ( I change the oil at 3,000 mile intervals). The problem is the fuel consumption. I dont 'cane' it and rarely does it go over 3000 rpm. Round town 28mpg, on a run 36mpg, over 3000 ,just to try it, you can see the fuel gauge vertually drop. I can detect no signs of any fuel leaks or dampness. The exhaust is very sooty, the bumper has soot on it. Its a Lucas pump. Normal running engine temp is 80 degrees. The air filter is new. The turbo starts to come in at about 1,700 rpm and it does go quite well from 2,000.
It has a new exhaust and clutch.
Any ideas ? I dont think it's me or should I say the way I drive but ????
Many thanks.
Cheers.
Geoff.
1991 Turbo diesel automatic.BX.
1993 ZX td. slowly dieing.
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Xaccers
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Post by Xaccers »

I get only slightly more from my 2.1TD estate.
When I first got it, it was very sluggish, not giving any power until around 3000rpm and of course for only a little bit over that.
I disconnected the battery for 5 hours while I got on with something in the house.
After re-connecting, it game me much more power lower down the revs, meaning I could change gear at 2500rpm rathe than over 3000.
Fuel economy seemed to improve although now it feels like it's getting sluggish again and economy is back to what it was.
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Post by mbunting »

That sounds very low to me, my 1.9 TD hatch used to get mid 40's without much trying, high 40's if you tried.

My current 406 saloon 2.1 with 197k on the clock doesn't go below about 45mph, have had it as high as 58mpg on a very steady economical run.

Check ALL the filters, check for binding brakes, tyre pressures, aerodynamic issues - ie. engine tray / wheel arch liners flapping etc.
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Post by deian »

Sounds wrong to me. First port of call if you have to turn it over for 4 seconds at cold would be the glow plugs, change them and it will start instantly hot or cold. When I had mine (210k when i sold it), it started so well it sounded like those old mini's half a turn and it would fire up.

As for the excessive fuel consumption, in relation to your black smoke, it sounds as if something is wrong with the mixture, it could be turbo related. Can you tell us if it smokes excessively with the turbo off boost (idle to when it starts spinning (1700rpm ish), on boost, or if you come 'off boost'? This may help others to work out the problem as it's not my area really.

Whats the air filter like? Have you checked all the pipes/ducting to and from the airbox and to the engine. Sounds like a sensor on the turbo solenoid or bad piping somewhere.

Finally as Xac said, try disconnecting the battery and see if it's better. Failing that get the ECU connected to a computer and see what fault codes it comes up with.
goldfinche
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Fuel etc.

Post by goldfinche »

Hello thank you that gives me something to think on. The brakes do not bind,air filter is new, when I have sorted the wiring on the BX then the Xantia will be investigated.
Standby, I will let you know.
Cheers.
Geoff.
1991 Turbo diesel automatic.BX.
1993 ZX td. slowly dieing.
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Post by Peter.N. »

My 2.1 XM regularly returns 40 - 50 mpg but I dont very often drive over 2,000 rpm and live in a rural area. The only difference in the engines as far as I know is that yours is electronically managed whereas mine is mechanical, so I wonder if you have a management problem. I suppose the cam belt hasn't been changed lately? could be a tooth out.
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Post by jeremy »

Once the engine is running the glowplugs will make no difference at all.

Black smoke and soot suggests poor atomisation - so it may well be the injectors are worn. It may be worthwhile trying a cleaner first and seeing of it makes any difference.

There is no mixture as such on diesels - their speed and power is determined by the amount of fuel injected. Obviously this is limited by the amount of oxygen available - hence the turbo for more power - allied to a system for getting more fuel from the pump.

Does your 2.1 have electrical connections to one of the injectors (no 2?)?

Does it sound 'right' or is it very noisy or quiet? If so there may be a timing problem.

Other things worth checking are damage to the inlet air trunking (all of it - for example has the inner and outer parts separated and is the inner restricting the air supply).
jeremy
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Post by lolingram »

If the cambelt is a tooth out is is unlikey to run at all well, which is not the case...
My 2.1 XM regularly returns 40 - 50 mpg but I dont very often drive over 2,000 rpm and live in a rural area. The only difference in the engines as far as I know is that yours is electronically managed whereas mine is mechanical, so I wonder if you have a management problem. I suppose the cam belt hasn't been changed lately? could be a tooth out.
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Post by CitroJim »

lolingram wrote:If the cambelt is a tooth out is is unlikey to run at all well, which is not the case...
Proved! One tooth out and the engine will barely run :o Been there, done that, got the T shirt :lol:
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Post by rory_perrett »

My 1997 2.1 is averaging around 47 mpg at the moment, its at 208k miles and still on the original injectors. Over an average of 5 tank fulls the best I've done is 52 mpg the worst is 42.

The car will run with the cam belt one tooth out but runs very rough, sounds like a load of nuts and bolts in a tin can but does display the characteristics you describe - down on power etc.
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Post by lolingram »

Goldfinche's didn't run rough though...
The car will run with the cam belt one tooth out but runs very rough, sounds like a load of nuts and bolts in a tin can but does display the characteristics you describe - down on power etc.
R.I.P. January 2010.
XM 2.1 auto VSX 1996 - Bosch Inj, Xantia HDi 90 estate 1999, Xantia 1.9TD 1997
Previously...
GS 1970, Dyane 1974, Xantia 94 VSX TD, XM 94, 2.1 auto - Lucas Inj, XM 92 2.1 estate - Lucas Inj
goldfinche
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Smoke.

Post by goldfinche »

Hello Jeremy and all. The funny thing is that it does not seem to black smoke or indeed smoke at all. I have had my son follow me and he said it was as clean as a clean thing! It does have a wire to an injector. It sounds not what I would describe as quiet with a degree of diesel knock on tickover, it sounds as loud as my BX 1-7 td. It's not the kind of hard knock from being over advanced.I was wondering about weather there is a temperature sensor (where??) for extra fueling when cold. and if this was playing about.
As regards the starting it has twice started instantly from cold. instead of the 4 seconds which is usual. I dont think it's glow plugs as when it does start there is no missing and its running on four at once.
I remain puzzled.
I will recheck everything and see if Ive missed anything.
Thank you.
Geoff.
1991 Turbo diesel automatic.BX.
1993 ZX td. slowly dieing.
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