Topic: What would cause high CO emissions on a 1995 2ltr (Read 19130 times)

Doctor Gollum · « **Reply #45 on:** 16 December 2019, 18:32:50 »

Italian tune up and retest immediately

Raeturbo · « **Reply #46 on:** 16 December 2019, 18:47:02 »

Indeed as post number two

dave the builder · « **Reply #47 on:** 16 December 2019, 21:24:02 »

shouldn't go open loop though
you still need to look at the fuel trims
just sneaking it past an MOT is not a long term answer ,
engine needs to run correctly or the new cat will die

Raeturbo · « **Reply #48 on:** 16 December 2019, 22:45:02 »

Engine breather blocked perhaps?

Andy H · « **Reply #49 on:** 17 December 2019, 03:33:49 »

The fans come on because the radiator is hot. The radiator is hot because the thermostat is open. It doesn't follow that the engine is fully up to temperature because you might have a faulty thermostat.

If the ECU is switching to open loop when the fans come on then it points to a faulty thermostat

The dash gauge over-reads on the pre facelift IIRC $:-\$ so I would trust the CTS over the gauge.You might have a faulty CTS but you can do a quick sanity check be seeing what it reads when the engine is cold.

.

Raeturbo · « **Reply #50 on:** 17 December 2019, 11:22:11 »

If you have an infra red temperature gun you could use that around thermostat area to see what’s really going on as it warms up. Great tool to have around and not too expensive,

Enceladus · « **Reply #51 on:** 17 December 2019, 15:16:58 »

I notice that on your original test natural idle was 790 RPM. That seems to be a bit high.
On your data capture cold start idle was 1378 RPM @ intake air temp = 2.7° and coolant = 28°
At the end of capture your idle was 768 RPM @ intake air temp =2.58° and coolant = 76°.
Idle is not much improved.

So your engine was warm when started?
Or the temp reading is way off at cold. It should be a lot closer to the air temp if the engine was really stone cold, left overnight.
Your engine never reached normal operating temp of 92°.
So the thermostat should never have opened.
In addition instead of gradually declining to a minimum, your idle has gone above 2k rpm whilst warming up.
And your best idle is fluctuating between 768 & 800.
The fluctuation might be the fans.

Is there any exhaust smell in the cabin?
Is there a vacuum leak somewhere? That would increase the idle speed.
And it seems to me that your engine temperature sensor might be foobar. That would explain over-fueling.
So why are the fans kicking in? Is the thermostatic switch on the radiator also foobar?

Perhaps try disabling the fan, pull the relay. Run your capture again. See does the engine temp go to 92° and what happens to the closed cycle.

Andy H · « **Reply #52 on:** 17 December 2019, 19:24:34 »

Forgot to mention - the thermostat should remain fully closed until the engine gets up to temperature.

Start the engine (from cold) and try holding the top hose - it should remain cold until the engine reaches close to the marked thermostat temperature.

If it gets warm before the engine reaches 92 degrees then fit a new stat. Everything else is a diversion if the stat is opening too early.

Enceladus · « **Reply #53 on:** 18 December 2019, 01:12:12 »

You mentioned a new temperature sender.
Was that fitted before your data capture?
Please confirm that it was the ECU sensor as opposed to the dashboard sender?
Was the new part fitted before of after the last emissions test?
Likewise before or after the open loop data capture?

addy · « **Reply #54 on:** 03 January 2020, 16:23:26 »

Sorry for the delay in replying. Not been too good. Changed both ECT sensor and Thermostat for new ones. The O2 sensor was changed before the ECT and Stat. Checked car today and it is still dropping between open and closed loop. The O2 sensor voltage seems to be erratic, when it is open the voltage is low, then when closed is high. As can be seen the Temp seems to make no difference, where it drops to open unless I have missed something.

I have recorded data at different temps. With no throttle, just letting everything warm up as normal. Sorry might not be in any particular order of opening.

https://drive.google.com/open?id=1s55aFlQAuT5AeAgKE_xrbGOysk2tg7rb
https://drive.google.com/open?id=1vjoP6jJtvrgiUj35HU0QIgFufcaQzC_r
https://drive.google.com/open?id=1DOVqoV_aNhgm1N_ZAaUoXPmjdmQ51NEh
https://drive.google.com/open?id=1WsgF0LuI0Y4X7I-1FkuMDIX-IIEyTgRE
https://drive.google.com/open?id=1octCW_v6exJQ36hHh2fWPDHrkTkBrk6t

Just to say All the best to everyone, for the New Year

Addy

dave the builder · « **Reply #55 on:** 03 January 2020, 17:28:40 »

I've said before about the engine speed ,possibly on another thread

you say all readings are with NO throttle yet reported engine speed is double or more than desired engine speed ,air leak ? what is the actual engine speed as per the dash when you idle ? 1400+ or 760 ish

if the ECU thinks the car is in acceleration at wide open throttle , or deceleration, then the ECU ignores the Lambda (open loop)
also open loop during warming up (over-fuels like a demented arsonist on a mission )
should only go closed loop (ECU uses data from lambdas ) when at Idle or part throttle operation when running at operating temperature

coolant temp voltage seems fine 4.5v cold to 1v hot

lambda voltage should bounce 200 to 800 ish millivolts not 4000+ (4 volts) when closed

dave the builder · « **Reply #56 on:** 03 January 2020, 17:35:39 »

also actual engine speed shows 0 in some sections of data , so either it stalled and re-started or crank signal lost and regained

as in "duff RPM sensor"
then i notice battery voltage zero in the same sections

addy · « **Reply #57 on:** 03 January 2020, 20:30:28 »

Sorry for all the aggro with live data. Recently had a stroke, which has taken out the communication part out, so lose what am saying and writing now and then. Only recently been able to drive. The part where it shows no revs, I think i caught the stop button, when bringin laptop out of sleep. Sorry

I have done 2 videos. 1st one shows idle from cold to tickover. (it is quite long)
https://drive.google.com/open?id=1-b3MOuY73zYZEQqWFO59Sv1US40zk119

2nd one shows revs and temp at nearly 80c on livedata.
https://drive.google.com/open?id=12usWgUhvVmSddleUzbzKCYGA6uoQFV4J

Livedata from nearly 80c
https://drive.google.com/open?id=1iMk0iuKaV121jebyf22kssGN8lLC5G24

Thank you all for your patience and help. It really is appreciated.

Best wishes for the New Year
Addy

Doctor Gollum · « **Reply #58 on:** 03 January 2020, 20:38:56 »

Coolant temp is still far too low.

Either unplug the fans for the emissions test, but watch the gauge, or replace the thermostat and report back

BTW, sorry to hear about your stroke, that alone is enough to worry about without car issues.

Andy B · « **Reply #59 on:** 03 January 2020, 21:15:40 »

Quote from: addy on 03 January 2020, 20:30:28

Sorry for all the aggro with live data. Recently had a stroke, .....

Sorry to hear that .... hope things improve and you get back to something like normal soon

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Author Topic: What would cause high CO emissions on a 1995 2ltr (Read 19130 times)

Doctor Gollum

Re: What would cause high CO emissions on a 1995 2ltr

Raeturbo

Re: What would cause high CO emissions on a 1995 2ltr

dave the builder

Re: What would cause high CO emissions on a 1995 2ltr

Raeturbo

Re: What would cause high CO emissions on a 1995 2ltr

Andy H

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Raeturbo

Re: What would cause high CO emissions on a 1995 2ltr

Enceladus

Re: What would cause high CO emissions on a 1995 2ltr

Andy H

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Enceladus

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addy

Re: What would cause high CO emissions on a 1995 2ltr

dave the builder

Re: What would cause high CO emissions on a 1995 2ltr

dave the builder

Re: What would cause high CO emissions on a 1995 2ltr

addy

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Doctor Gollum

Re: What would cause high CO emissions on a 1995 2ltr

Andy B

Re: What would cause high CO emissions on a 1995 2ltr