Fiesta failed on emisions

[Ticker]

Hi to all

I am repairing a Fiesta 1117cc 1993 with CFI
for a MOT retest one of the failure items is emisions like

fails CO test 0.79
passes HC at 178
Lambda pass at 1.03

so to sum up just fails on the CO should be up to 0.30 max
I guess the cat has failed do you agree as this car belongs to a student and
I am trying to
keep costs down.
The engine has had a full service in the last 6 x months

thanks in advance
mike

[mrcheerful]

"Ticker" <m.deakes@blueyonder.co.uk> wrote in message
news:h%Scd.104966$BI5.96853@fe2.news.blueyonder.co .uk...
> Hi to all
>
> I am repairing a Fiesta 1117cc 1993 with CFI
> for a MOT retest one of the failure items is emisions like
>
> fails CO test 0.79
> passes HC at 178
> Lambda pass at 1.03
>
> so to sum up just fails on the CO should be up to 0.30 max
> I guess the cat has failed do you agree as this car belongs to a student
> and I am trying to
> keep costs down.
> The engine has had a full service in the last 6 x months
>
> thanks in advance
> mike
>

It sounds most like the car was not fully stinking hot, I have several of
these that have the same symptoms but they pass if they are really hot.

mrcheerful

[Timo Geusch]

Ticker was seen penning the following ode to ... whatever:
> Hi to all
>
> I am repairing a Fiesta 1117cc 1993 with CFI
> for a MOT retest one of the failure items is emisions like
>
> fails CO test 0.79
> passes HC at 178
> Lambda pass at 1.03
>
> so to sum up just fails on the CO should be up to 0.30 max
> I guess the cat has failed do you agree as this car belongs to a student and
> I am trying to keep costs down.

You may well have guessed wrong, it could be the lambda sensor as well
(and that's somewhat cheaper to replace...). I'd get it hooked up to
some proper diagnostic equipment first as that may well point you in
the right direction.

> The engine has had a full service in the last 6 x months

Which probably makes bog-all difference if one of the engine
management sensors has gone south.

--
Timo Geusch
'92 Nissan Skyline GTS-T

[George Spigot]

"Ticker" <m.deakes@blueyonder.co.uk> wrote in message
news:h%Scd.104966$BI5.96853@fe2.news.blueyonder.co .uk...
> Hi to all
>
> I am repairing a Fiesta 1117cc 1993 with CFI
> for a MOT retest one of the failure items is emisions like
>
> fails CO test 0.79
> passes HC at 178
> Lambda pass at 1.03
>
> so to sum up just fails on the CO should be up to 0.30 max
> I guess the cat has failed do you agree as this car belongs to a student
and
> I am trying to
> keep costs down.
> The engine has had a full service in the last 6 x months
>
> thanks in advance
> mike
>
>
my favorite on those is fuel pressure
--
George

[Andy Hewitt]

Ticker <m.deakes@blueyonder.co.uk> wrote:

> Hi to all
>
> I am repairing a Fiesta 1117cc 1993 with CFI
> for a MOT retest one of the failure items is emisions like
>
> fails CO test 0.79
> passes HC at 178
> Lambda pass at 1.03
>
> so to sum up just fails on the CO should be up to 0.30 max
> I guess the cat has failed do you agree as this car belongs to a student and
> I am trying to
> keep costs down.
> The engine has had a full service in the last 6 x months
>
> thanks in advance
> mike

Check the throttle position sensor first, these can cause over fuelling,
and are *extremely* common.

You also need to check the vacuum pipe to the MAP sensor (on the
bulkhead), these get filled with fuel and eventually perish and
collapse. If so, then you need to replace it, and also fit the one way
valve too.

Check that the breathers are clear too, these commonly gunge up.

What kind of 'full' service? If it was a Kwik-Fit type place then
suspect that a full service wasn't carried out completely.

Check also valve clearances and plug gaps.

Than, as already said, get it stinking hot before you take it back for
the retest.

--
Andy Hewitt ** FAF#1, (Ex-OSOS#5) - FJ1200 ABS
Honda Civic 16v: Windows free zone (Mac G5 Dual Processor)
http://www.thehewitts.plus.com

[Tim \(Remove NOSPAM.]

"Ticker" <m.deakes@blueyonder.co.uk> wrote in message
news:h%Scd.104966$BI5.96853@fe2.news.blueyonder.co .uk...
> Hi to all
>
> I am repairing a Fiesta 1117cc 1993 with CFI
> for a MOT retest one of the failure items is emisions like
>
> fails CO test 0.79
> passes HC at 178
> Lambda pass at 1.03
>
> so to sum up just fails on the CO should be up to 0.30 max
> I guess the cat has failed do you agree as this car belongs to a student
and
> I am trying to
> keep costs down.
> The engine has had a full service in the last 6 x months

Fiesta CFi's can be sods, make sure the motor is fully hot before the test
and that the thermostat is allowing it to be- the gauge should be reading in
the middle of the NORMAL section. Any less- change the 'stat and give it a
hard fast run at motorway speed just prior to the test so its really hot.

If it still fails then favorites on the CFI are faulty Air temp and water
temp sensors- check the ATS first- they tend to get melted if the engine's
ever spat back through the inlet manifold- quite common!

Tim..

[Dave Plowman (News)]

In article <kuTcd.10939$xb.8754@text.news.blueyonder.co.uk>,
mrcheerful
. <nbkm57@hotmail.com> wrote:
> It sounds most like the car was not fully stinking hot, I have several
> of these that have the same symptoms but they pass if they are really
> hot.

If it's got a cat and is newer than a certain date, don't the MOT people
measure the oil temp before taking readings?

--
*You never really learn to swear until you learn to drive *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

[Graham]

On Mon, 18 Oct 2004 17:24:29 GMT, "Ticker" <m.deakes@blueyonder.co.uk>
wrote:

>Hi to all
>
>I am repairing a Fiesta 1117cc 1993 with CFI
>for a MOT retest one of the failure items is emisions like
>
>fails CO test 0.79
>passes HC at 178
>Lambda pass at 1.03
>
>so to sum up just fails on the CO should be up to 0.30 max
>I guess the cat has failed do you agree as this car belongs to a student and
>I am trying to
>keep costs down.
>The engine has had a full service in the last 6 x months
>
>thanks in advance
>mike
>
Assuming that the engine was hot and assuming there are no air leaks
at all (inlet or exhaust) then a lambda figure of 1.03 says that the
mixture is on the weak side and there should be Ox present in the
exhaust to "feed" the cat. Generally a failed temp sensor, lambda
sensor etc would create a rich mixture and the lambda reading would be
below 1.0 i.e. 0.92

A CO of 0.79 is not mega high, so from those figures I would be
suspecting a very weak or failed cat.


Regards,
Graham L
http://www.lambdasensor.com
http://www.injectorcleaning.co.uk

[milktray]

Will the low HC figure not indicate that the cat is working as it should though?

[matt773]

Obviously a common problem - mine failed fast idle test on CO reading of 0.42 when max allowed is .30. I got hold of a tester that said throttle position sensor was faulty, replaced sensor and got identical readings on retest. I replaced lambda sensor last year, but I suppose it could have failed. I have also heard that fuel return pipe can get blocked and cause overfuelling but haven't investigated yet. Garage man says he reckons it is not the CAT.
I will try some of the previous suggestions, but any further advice would be welcome.
Matt