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CO2 Limits
mistergrumpy - 18/3/09 at 08:23 PM

Anyone any idea as to what the limits re on a ZX9 Locost. Ballpark figure will do. I've had a look through the SVA manual and all I can find is post 95 engines needing to be <0.3% Me and Gav just did mine and it was about 2.7%. That's with an R1 can which has its own cat plus another cat on there as well.


Paul TigerB6 - 18/3/09 at 08:31 PM

thats a pre Aug 95 ZX9 engine?? If so its 1200ppm Hydrocarbons and 3.5% CO (not CO2)


mistergrumpy - 18/3/09 at 08:35 PM

Sorry no mines a 98 engine. It surely can't be <0.3%.


Paul TigerB6 - 18/3/09 at 08:45 PM

quote:
Originally posted by mistergrumpy
Sorry no mines a 98 engine. It surely can't be <0.3%.


and 200ppm HC - yup!! Sounds like the engine is running very rich and /or the cat needs to be a lot hotter!! Rev the nuts off it and see if the figures fall as it doesnt appear the cat is doing much at the moment (they need to be hot to get below SVA emmissions levels.)


adithorp - 18/3/09 at 08:46 PM

Yes, it's 0.3 max.
Sounds like your cat isn't up to temp. It can take 15min of "spirited" driving or longer if just reving it in the workshop. Untill the cats get to temp they won't do diddly squat then they'll suddenly light up and the numbers will fall. 2.7% is probably a bit rich but the cats will drop it spectacularly once they work. You just need to rev the tits off it for long enough.


Paul TigerB6 - 18/3/09 at 08:52 PM

Just to add - the 0.3% figure is the fast idle test. Tickover is 0.5% CO


mistergrumpy - 18/3/09 at 08:54 PM

Sweet Jesus, I'm in the sh1t now
The engine seemed up to idle temp and the fan was kicking in intermittently. The exhaust wasn't too hot to touch though. I've tried the colourtune and that has it alright. Maybe a daylight revving session is in order then. 0.3%!!!!
Cheers for the help lads.

[Edited on 18/3/09 by mistergrumpy]


Paul TigerB6 - 18/3/09 at 08:57 PM

The engine might be up to temp but the cat wont be (especially if its just in front of the can). Definately need to revs the bowlocks off it in the daytime to get the cat working - it simply wont get close ticking over in the workshop no matter how long you leave it. Wrapping the exhaust may help you get the cat hot (even if it falls off after SVA)


mistergrumpy - 18/3/09 at 08:59 PM

Cool, I'll give that a try. Thanks Paul. It is in front of the can. I think MNR rent one out that's the same.


Paul TigerB6 - 18/3/09 at 09:21 PM

No problem at all - let us know how you get on. As Adrian says, they seem to have a critical minimum operating temperature and once you hit that, the figures will drop pretty quickly.


adithorp - 18/3/09 at 09:39 PM

The cat has to hit 480'c+ before it works. Nothing untill then and then as if by magic it'll drop the CO to close to zero. Not a gradual fall as it warms.

adrian


iiyama - 18/3/09 at 09:46 PM

Wonder if thats the problem I had then? Failed yesterday on emissions but only on lambda, (slightly high).

Fan and leccy water pump were doing the job of keeping water temp to 85 but maybe I should increase the stat settings?


adithorp - 18/3/09 at 10:08 PM

quote:
Originally posted by iiyama
Wonder if thats the problem I had then? Failed yesterday on emissions but only on lambda, (slightly high).

Fan and leccy water pump were doing the job of keeping water temp to 85 but maybe I should increase the stat settings?


It's not to do with the engine temp. It's the cat temp and the exhaust gasses heat that. A few degrees of engine temp won't make a difference.

If it was just the lambda you failed on it's not a cat temp fault. If your only slightly high (what were the actual readings) on lambda then you're either slightly weak or you have a small air leak on the exhaust. That'd draw oxygen in and give a high reading.


iiyama - 18/3/09 at 10:22 PM

Interesting. Can was leaking so as it is a tool to get through SVA and MOT's it was welded up. Cant see that air could be getting in anywhere else unless its round the block of plates where the PAIRs valve was. Map was set weak but wondering now if its too weak.

Cant remember the exact figure but I should get the details in the post tomorrow morning so Ill post 'em then.


twybrow - 18/3/09 at 10:26 PM

Do you literally sit with the engine revving at say 2/3rd maximum revs for 15 minutes (wincing with mechanical sympathy!)? I am setting mine up properly next week, so I would be intrigued to know how long and how hard (oh err) people have revved their BECs before taking a reading....?


nstrug - 19/3/09 at 08:38 AM

I did the speedo and the noise test before the emissions test - this was enough to get the cat working.

With a 2003 R1, with cat, powercommander and air injection I got:

Fast Idle:
CO 0.1
HC 12
lambda 1.00

Natural Idle:
CO 0.01

Do you have air injection? It can help hugely as the cat can only oxidise CO to CO2 if there is oxygen available to actually do the job. The air injection also helps to burn off excess HC - which has the happy side effect of heating the cat up to operating temperature.

Nick


nstrug - 19/3/09 at 08:40 AM

I did the speedo and the noise test before the emissions test - this was enough to get the cat working.

With a 2003 R1, with cat, powercommander and air injection I got:

Fast Idle:
CO 0.1
HC 12
lambda 1.00

Natural Idle:
CO 0.01

Do you have air injection? It can help hugely as the cat can only oxidise CO to CO2 if there is oxygen available to actually do the job. The air injection also helps to burn off excess HC - which has the happy side effect of heating the cat up to operating temperature.

Nick


twybrow - 19/3/09 at 10:21 AM

i have secondary air injection (ie a small valve that opens in the airbox, and purges air into the throttle bodies at idle - is this what you mean?


adithorp - 19/3/09 at 01:04 PM

My cat' took 20 min reving at 6-7000rpm before it started to work when I adjusted it at my mates MOT station. The fan was running after about 5min. I drove (10 miles up motorway) to the retest and they did the test first as soon as I arrived.
The exhaust gasses are hot enough but you've got to put the heat in quicker than the cats radiating it out. My headers were cherry red long before the cat started working!

adrian

ps. No, it dosen't feel right doing it.


iiyama - 19/3/09 at 01:13 PM

Test report just came in.

Fast ide CO% limit = 0.3. Actual reading = 0.03

HC ppm limit = 200. Actual reading = 114

Lambda 0.97/1.03 actual reading 1.09

Natural idle passed, (limit 0.5. actual 0.02)

The report states that it only failed in the last 5 secs of a 30 second test.


adithorp - 19/3/09 at 08:02 PM

Assuming your exhaust isn't drawing air somewhere...

It appears yours is just a bit weak. However I'd expect your CO to drop almost to zero if it was weak once the cat's operating.

The problem is, because its an open loop system (ECU isn't getting lambda readings and adjusting mixture constantly like a modern tin-top), any slight variations in the throttle can throw things out and its tricky getting steady readings. On my first test I had variations as the fan cut in and out. For the retest I temporarily wired the fan to run constant and it was a lot easier to control.

adrian


mangogrooveworkshop - 19/3/09 at 08:11 PM

Fresh spark plugs are a must......


iiyama - 19/3/09 at 09:06 PM

Plugs are new.

Ill get it on a gas analyser @ an MOT station locally. want to be sure to pass @ the retest...


mistergrumpy - 26/3/09 at 07:07 PM

Just to mention. I tested the car again but placed it on the top of the drive where it's clear on both sides. I've wrapped the cat now as well.
I tested it as per the instructions and revved the spuds off it as Adi recommended. I got 3.5 on tickover and it went down to about 1-2 when I revved it to 3500rpm so pleased at that. I think the area that I was testing it in was a little restrictive for the fumes and was throwing things. Also as a bit of a bargain all the exhaust wrap seem to have noticable dropped the noised. Not loads but I was only 1 dB over anyhow.