Xantia failed smoke test

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Re: Xantia failed smoke test

Post by Jaf »

My car failed the ITV a couple of years ago. 2 things, waiting for the test the engine had got cold, and didn't thrash her on the way there. The inspector told me to drive round the block fast, which I did and then she passed. I rev her hard on the way each time now, never a problem.

You only get the first retest free though.
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Re: Xantia failed smoke test

Post by elma »

I was a bit concerned about emissions at the last mot so I drove there in 2nd gear. The car got a "fast pass" and the tester said he was surprised as normally he has to rev the life out of an old diesel after it fails to get it to just pass.
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Re: Xantia failed smoke test

Post by Stickyfinger »

Rule of Thumb for an MOT....

No 1............. NEVER test a cold car, all test figures are based on engines/cats at full operating temp.
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Re: Xantia failed smoke test

Post by lazza »

If I run a mix of vegetable oil with petrol for a while, will this help clear the injectors??
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Re: Xantia failed smoke test

Post by elma »

I don't think it would. Some injector cleaner will, don't put it in before an mot or equivalent though as it creates exhaust smoke while it does its stuff.
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Re: Xantia failed smoke test

Post by chinkostu »

Run some injector cleaner through via the fuel filter? Drain a bit out and top off with cleaner? Will run like crap for a few minutes like!
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Re: Xantia failed smoke test

Post by lazza »

I've noticed there are two adjusters on the Bosch VE fuel pump-

- Full-load screw adjusting screw
- Smoke adjustment on top of the diaphram

Which of these should I play with to reduce the full throttle smoke??
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Re: Xantia failed smoke test

Post by chinkostu »

The screw on the top of the pump adjusts the height of the LDA pin before boost. Futher down - more fuel. The one on the side of the pump adjusts fuelling across the whole range. Might be worth winding the top one out all the way
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Re: Xantia failed smoke test

Post by MikeT »

The "smoke screw" on top, is for off-boost fuelling, which will affect smoke as you pull away from standstill (low-ish rpms). The MOT test (at least in the UK) concentrates more on full power smoke which is related more to the other adjustment you mention.
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Re: Xantia failed smoke test

Post by chinkostu »

MikeT wrote:The "smoke screw" on top, is for off-boost fuelling, which will affect smoke as you pull away from standstill (low-ish rpms). The MOT test (at least in the UK) concentrates more on full power smoke which is related more to the other adjustment you mention.
You can also take the top off and rotate the LDA to a more agressive profile for more fuel. Need to adjust boost afterwards though
Stu

Cars
1995 Xantia 1.9TD SX in (faded) Red
2003 Fiesta 1.4 Zetec in GREEEEEEEN
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1999 Punto :oops:
1996 306 1.8 XN Auto :?
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Re: Xantia failed smoke test

Post by MikeT »

chinkostu wrote:
MikeT wrote:The "smoke screw" on top, is for off-boost fuelling, which will affect smoke as you pull away from standstill (low-ish rpms). The MOT test (at least in the UK) concentrates more on full power smoke which is related more to the other adjustment you mention.
You can also take the top off and rotate the LDA to a more agressive profile for more fuel. Need to adjust boost afterwards though
True, except the aim of this post is to reduce fuelling/smoke :-D
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Re: Xantia failed smoke test

Post by chinkostu »

MikeT wrote:
chinkostu wrote:
MikeT wrote:The "smoke screw" on top, is for off-boost fuelling, which will affect smoke as you pull away from standstill (low-ish rpms). The MOT test (at least in the UK) concentrates more on full power smoke which is related more to the other adjustment you mention.
You can also take the top off and rotate the LDA to a more agressive profile for more fuel. Need to adjust boost afterwards though
True, except the aim of this post is to reduce fuelling/smoke :-D
True :rofl2:
Stu

Cars
1995 Xantia 1.9TD SX in (faded) Red
2003 Fiesta 1.4 Zetec in GREEEEEEEN
2001 206 1.9 LX
2001 Saxo VTR
1999 Saxo 1.1 East coast
1999 Punto :oops:
1996 306 1.8 XN Auto :?
1996 Fiesta 1.3 #-o
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Re: Xantia failed smoke test

Post by Stickyfinger »

it may be a "Need" but should never be an "Aim" :)
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Re: Xantia failed smoke test

Post by BX »

Loosen the lockout on the screw on the back of the pump (RH side as you look in at it). Screw out the screw about 1/4 turn (anticlockwise). It will leave you down on power throughout the rev range but will greatly reduce smoke. After the test reverse the process. On the other hand as I suggested before throw a bottle of dipetane in the tank the day before the test. Give it a good hard run. I have never seen a smoke reading above 1.5 with dipetane in the tank.
I am sure that there are other brands that will do the same. I think STP also sell what they call an NCT pack here. It will reduce emissions at least well enough to get you through the smoke test.
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Re: Xantia failed smoke test

Post by chinkostu »

Stickyfinger wrote:it may be a "Need" but should never be an "Aim" :)

Mine hazes like mad on full boost, need to wind the wastegate up! But it picks up so much better
Stu

Cars
1995 Xantia 1.9TD SX in (faded) Red
2003 Fiesta 1.4 Zetec in GREEEEEEEN
2001 206 1.9 LX
2001 Saxo VTR
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1999 Punto :oops:
1996 306 1.8 XN Auto :?
1996 Fiesta 1.3 #-o
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