R500 K Emissions. HC 1,000ppm Solved again - several years later.

[anthonym]

HI! YES! We are tested only as to:

CO2 > 12%

CO < 0.5%

HC < 100ppm

at 950 rpm +/-50

The very first test when the car had only warmed at idle was steady with all three acceptable, but ever since inlcuding a hot run or two I have been unable to get the CO below 0.5, mostly at about 1.4 to 1.7 .

I've tried increasing and reducing the mix, but to little avail.

However, for today very pleased that the new throttle bodies have solved the massive 2000ppm HC problem we now know as suspected was caused by the 40% reduced airflow on No3. 

Education about CO welcome :-)

I have been wondering if the cat is "unhappy" following several years excessive HC being dumped on it.

Anthony

p.s. lack of oxygen, does that mean increase the idle airflow all currently at about 5.5 - it's hard to be precise because the airflow meter jumps from 5 to 7.

Another possibility is to try to make the balance between the pair of TBs even more accurate.

 

[aerobod - near CYYC]

The cat maybe too melted from rich use over the years and lacks efficiency, but you could still increase the airflow very slightly. I don’t think you have far to go, as the values are getting very close to good stoichiometric emission values, especially if the cat isn’t working well. 0.5% CO is about as low as you can get without the cat helping.

This is what catless emissions would be like:

 

[anthonym]

tomorrow we fit the new TPS and see if that helps.

 

p.s. for future readers we used the old worn TPS today because have had to modify the new TPS bolt holes with a drill  to make them larger so the TPS can be swivelled a tiny bit to get the Kohms reading or TPS location number we desire to match in the ECU. (To use the ECU TPS Reset feature (Ctrl-T) is  n o t  what our map expert wants us to do).  

[revilla]

I doubt it will be a TPS issue. I'm voting tired cat too. You've got partially burned carbon (CO) and some residual oxygen (O2) in your exhaust stream. When properly hot, the catalyst should be using the O2 to oxidise the CO to CO2. Errr ... You do have a cat, don't you?

[CageyH]

Was the cat hot?

[anthonym]

TPS: no me neither really, but it's the last old part to be replaced.

yes have a cat.

Was it hot? I was wondering how we know this. Yes the oil was hot at over 80 and the coolant 90 (it's currently set to run hotter for now), but how fast does the cat cool? While I could heat it up going up the mountain, getting down again allowed it to cool from the climb. I tried a shorter run so going down and then up to home but that outing isn't so far. Possibility is to run up the mountain and test the emissions somewhere up the hill rather than returning home.

Something confusing me is that when first we switched on and idled to operating temp, all the readings were within parameters and steady. I never saw the CO below 0.5 after that. I've ordered some "Cataclean" as an interim possibility, but it won't be here for a week. 

The cat is inside the silencer, the end caps are welded on; Powerspeed exhaust. I'll see if I can speak with Dave in the morning, but also was wondering if any proficient garagist can replace the cat instead of taking the car 1,000 miles at a cost of circa £1k and a week of my time. I think the cat itself is about £250 within that 1k and I think that is fitted. £500 is travel costs there and back. £250 is accommodation, fuel etc while in GB. I was planning to replace it as part of this coming Winter's engine rebuild.

Looking at James' graph (thanks James), it looks like it's just possible to get HC under 100ppm while CO is less than 0.5%, but I presume careful mapping would be required, so I have been offered a remote session by Steve G to do that maybe next Sunday or hopefully soon after. Assuming the cat is not being helpful.

I have deferred the "expertise" (M.o.t.) until 29/08 from 7/08, but it's still illegal to run about without the emissions certificate up to date, except for testing etc.

anthony

[revilla]

I know I shouldn't be saying this but given that it's up for a refresh this year and given that it's so very close now ... OK so it's Switzerland so probably unlikely, but there's nowhere "friendly" who might let it slip through with a little "encouragement" is there?

[CageyH]

If the cat does not take to being cleaned, then personally I would look at buying a new silencer and having it shipped. The new one would be kept for MOT use, and I would use the other one for everyday use.

[SM25T]

It's a hell of a silencer on this car !

[CageyH]

It is probably still cheaper than going back to the UK to get it fixed.

[SM25T]

We may be nearer happiness. Give it an hour.....

[SM25T]

Sorted. Remove and refit plugs ... this time tight enough to seal the (as found) uncrushed washers ... replace original old TPS. Values all now legal.

[anthonym]

[anthonym]

Nirvana - see below

All entries from minute 1 to minute 14 from warmish. See next post for more.

Bottom two lines - CO and CO maximum straight line = 0.5%

Next straight line up at 1.00 is HC max of 100 ppm 

Next line up sort of straight is Lambda (target = 1.00 )

Top line mountainous is HC 

Minute 11 in to 12 shows impact of the fan kicking in and then off - Fan has been set at 95c on 90c off for these tests.

 

[SM25T]

Above graph shows HC, lambda and CO ... each minute from a lukewarm start. CO good from minute 2. HC needed about 13 minutes for cat and oil to warm up.

[SM25T]

Right hand column is water and oil temp.

[CageyH]

Good work.

[anthonym]

and finally, this evening, car fully sorted. I hope.

thank you everyone.

anthony

[anthonym]

It is 4 years later and we have the same trouble, this time following R500 K engine refresh.

I have been using this thread as a sort fo check list. 

I can get HC down to 200 or 300 ppm, but the magic 100 is eluding me. Wishing I had replaced the cat while she was over there. That said she has hardly done any miles since 2019 so the cat is pretty much the same as it was back then.

I am wonderIng how much difference is made by any change in timing, however small.

Retarding the spark?

Balancing the barrel pairs:

The Minister guide recommends a total of 10 airflow for each pair of roller barrels.

MY 1&2 are 4.5 + 4 =8.5 with no attempts yet to change this

MY 3&4 can be anything between combined 7 to 11 - these I have been adjusting for a couple of days.

Lambda is always less than 1 so she is running rich, in 2019 it was always > 1 so was running lean. I am tempted to think I need to open up 1&2 a bit. However, I think changing these has other affects on the mapping.

The test is at 970 RPM ONLY

 

Anthony

Emerald K6 / R500 K from year 2000 

[anthonym]

ok so thanks for the private responses. I think we have a working solution. The work solution is/was

to increase airflow on the front pair to 10 total

balance 3&4 to that

reset Emerald to new throttle position (by the Two Steves not me, so not sure the exact mapping process)

Tweak other bits of the mapping (ditto)

Got to around desired figures without a run, but never perfect.

(next day) went for a short run, after filling with 98 replacing the 95 octane - relevant? Don't know.

During (rather wet rainy) run nothing over 4,000 rpm, stopped, tested emissions, saw perfect figures. 

Returned home after stop at shop 30 seconds before home, emissions worse, so it is very sensitive to being tested immediately after a run without switching off - at tickover only.

C'est tout.

Anthony

 

[anthonym]

So we passed with emissions  from R500K at 970 rpm as follows:

CO 0.07 (max 0.5)

CO2 13.38% (Min 12,5%)

HC 56 PPM (Max 100)

The very short solution to all this was roller barrel balancing.

a t b

special thanks to all those who helped, could not have done it without you.

Anthony