cloudy
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| posted on 25/3/09 at 05:22 PM |
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Wierd non CAT emissions fail...
Looking for some advice on things to check,
Just failed SVA on emissions on a pre 95 engine
It's running beautifully, no smoke, idles clean and all pipes warm equally..
Left Exhaust:
CO 0.22% HC 1608
Right Exhaust:
CO 0.39% HC 2951
Limits:
CO 3.5% HC 1200
Any ideas what I should be looking at here? There are no running problems with the thing whatsoever...
James
www.warnercars.com
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matt_claydon
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| posted on 25/3/09 at 05:32 PM |
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It's running too rich, hence the unburnt fuel in the exhaust.
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theconrodkid
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| posted on 25/3/09 at 05:37 PM |
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running weak will cause high HC,just richen it up a bit
who cares who wins
pass the pork pies
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rusty nuts
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| posted on 25/3/09 at 05:37 PM |
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Look at the CO figures, it's running too weak! The hydrocarbons will drop if it's richened up. As to whether or not it will reduce them
enough? the only way is to adjust it and recheck. If HC is still too high there is a problem with the engine/ignition . There should be some other
figures , post them up.
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cloudy
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| posted on 25/3/09 at 05:42 PM |
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Thats that only two figures measured on the non CAT test...
The tester thought it was too lean too....
Trouble is without a gas tester I have no way to tune it...
Do I need to be twiddling the idle screws mixture screws?
James
[Edited on 25/3/09 by cloudy]
www.warnercars.com
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SeaBass
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| posted on 25/3/09 at 05:44 PM |
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This document is good:
http://www.autoshop101.com/forms/h56.pdf
I've learnt something today!
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cloudy
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| posted on 25/3/09 at 05:49 PM |
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That graph is pure gold - thanks! Would estimate AFR up at 22!
Could I tune it by welding in mounts for ox sensors in the headers and then using an AFR guage to get it right?
James
www.warnercars.com
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SeaBass
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| posted on 25/3/09 at 05:52 PM |
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Could you have an air leak on the inlet manifold?
What engine is it? Carbs?
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cloudy
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| posted on 25/3/09 at 05:55 PM |
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carbs on a gsxr 1100wp, definately no intake leaks, replaced the carb rubbers a while back...
James
www.warnercars.com
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flak monkey
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| posted on 25/3/09 at 05:59 PM |
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Yep defo too weak. There should be some idle mixture adjustment screws on the carbs. Probably underneath, and possibly under some covers. Unscrew them
0.25 of a turn and have another go. The SVA man might let you twiddle with them on the machine once you know where they are and how to adjust it.
The other option is speak to a local garage and see if they will let you borrow their gastester for 30mins (you will need to book it in for an
'MOT' to be legally allowed to drive it there though).
David
Sera
http://www.motosera.com
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BenB
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| posted on 25/3/09 at 06:07 PM |
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A colortune is quite helpful here. I've got a bike one for a ST1100 (10mm). Feel free to borrow it if you want. Very useful in my experience for
setting up the idle mixture....
[Edited on 25/3/09 by BenB]
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cloudy
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| posted on 25/3/09 at 06:12 PM |
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That might be handy - I'm on the lookout for an AFR gauge - but it means welding in bungs in all the exhaust headers...
Whereabouts are you? Could I paypal some money for you to post?
James
www.warnercars.com
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BenB
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| posted on 25/3/09 at 06:29 PM |
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I'm in London (NW6). End of the M1....
I can post it, but it'll probably be the weekend before I get to the garage so you'ld have it middle of next week???
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cloudy
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| posted on 25/3/09 at 07:04 PM |
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My neighbours just told me he has a 2 gas analyser and a colourtune!
job done!
www.warnercars.com
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DIY Si
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| posted on 25/3/09 at 10:29 PM |
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Are the carbs set up for the better exhuast and air filter? I had this with my first engine. Was told it had been set up right by the previous owner,
only to find at MOT time that it was running lean. With the new engines and carbs it was rich with a stock air filter. Removed it and the emissions
dropped straight into the green on the MOT computer. The new stuff had been set to run with a decent filter and exhaust, the old stuff hadn't.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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cloudy
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| posted on 25/3/09 at 10:38 PM |
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stock air box, and the exhaust is more restrictive if anything....
James
www.warnercars.com
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cliftyhanger
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| posted on 26/3/09 at 10:29 AM |
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another thought, are the carbs balanced spot on? They are weak, but poor balance can wack the HC right up. Ans a pipe in the ear is probably not
accurate enough...though if miles out should help get into the right ballpark.
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cloudy
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| posted on 26/3/09 at 10:08 PM |
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Have reset the idle screws using a colourtune and 2 gas analyser...
They were slightly off book settings, and came good around the book setting...
The left side moved to about 2% CO and 1400 ish HC's a little tweaking got it down to 880HC's - a pass. The right hand side I can't
get close - managed about 1400HC absolute best...
Ignition is dyna 2000, dyna coils, dyna leads, new iridium plugs, all plugs correct colour, no carbon or oil, engine idles and runs perfectly.
I'm at a complete loss - it shouldn't be this hard right?
James
www.warnercars.com
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rusty nuts
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| posted on 27/3/09 at 06:54 PM |
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If the engine has adjustable tappets , shim or otherwise, test for tight tappet clearance. Also check plugs, leads etc and if you have a compression
tester check compressions. A cylinder that is not running correctly may not show up as a misfire but will show up as increased hydrocarbons.
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cloudy
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| posted on 27/3/09 at 08:21 PM |
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I will balance the carbs tomorrow, I dont have access to a compression tester, so i'll have to try and buy one (won't be in time)
I did check the timing (I can time the two pairs seperately and 2 and 3 were about 3 degrees out which can't help)
Will balance carbs then try again tomorrow, I don't think i'm going to be able to do it... Sods law says even if I scrape it through at
home it'll be high at SVA
James
www.warnercars.com
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BenB
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| posted on 27/3/09 at 10:17 PM |
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Offer of a compression tester also stands 
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cloudy
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| posted on 28/3/09 at 09:07 AM |
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Thanks ben, i'll see how I get on today and give you a shout, I think if I can't sort emissions today i'll have to cancel SVA on
tuesday anyway as it could be serious engine work...
James
www.warnercars.com
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cloudy
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| posted on 28/3/09 at 12:18 PM |
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A good balance has got them down to 2%CO and hovering between 1200 and 1500 both sides now... Still not close enough
Cam cover off and all the valve clearances are bang on the middle of the the tolerance - can I take you up on the comp tester offer ben?
www.warnercars.com
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cloudy
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| posted on 28/3/09 at 04:24 PM |
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Closer, got it to 3% CO and 1100 HC, but ONLY when the headlights are on!! about 1250 without....
If I drop the idle revs to match the loaded state, HC's stay high...
Hopefully SVA man lets me leave the lights on for the test, but anyone got any ideas what that might suggest as the problem?
James
www.warnercars.com
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cloudy
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| posted on 28/3/09 at 09:32 PM |
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Found an intake leak on 2 and 3, but i'm not sure it's going to make a great deal of difference (after all 2 is part of the left pair
which is giving an OK reading)
I have a dyna2000 ignition which I believe runs 4 degrees advance over stock (40) at idle... Would it be worth pulling this back to zero?
James
[Edited on 28/3/09 by cloudy]
www.warnercars.com
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