Can anybody help.Have got mk gt1 with Yamaha thunderace engine in it,have had car moted and passed emissions,readings as follows fast idle 0.17 limit 0.30,lambda 1.0 limit 0.95 to 1.09,natural idle 750 to 950rpm 0.33 limit 0.50. Car has large car cat fitted close to exhaust manifold collector and has later r1 end can with cat in it,so has 2 cats,everthing else is standard and hasnt been touched airbos mixture jets on carbs etc,all untouched.
Now for the problem took it for SVA on 31st May failed on emmissions only thing different was rear end was off car when tested could it have failed due to not getting as hot ? The results of the sva test are fast idle limit 0.30 recorded 1.15, lambda passed, recorded 0.98 limit 0.97 to 1.03,hydrocarbons passed 72, limit 200,natural idle 0.96 failed limit 0.50,can anyone suggest any quick fixes as is rebooked for Tuesday 7th june.

Thanks Simon

will try anything thanks snoopy.

Regards Simon.

Simon, you have my sympathy.
I eventually passed the emmissions test by bypassing all the Llambda bleed gubbings and getting the cat 'kin hot. And I mean 'cherry red'

Good luck
John

best bet for the emissions is to get some heat rap to place round the cat this will help keep the heat in the catalyst
best bet just before emissions test is to rev the car hard five or six times to get the cat really working, we have passed three cars like this
1 x fireblade
2 x r1
both on carbs, and incidently without using air bleeds and a like just using the mixture screws

hope this helps

good luck with the retest

best regards

marc

Retarding the ignition by 5-10 degrees will get the exhaust hotter and up the efficiency of the cat. I did read once that adding alcohol to the tank improves burn efficiency and reduces emissions. Can't remember percentage or what type, meths or ethanol. Double scotch anyone?

wind your mixture screws in half a turn or more (weaken them off)
theres room for you lambda to go higher,your lambda looks like its running rich
this will bring you CO down for both fast idle and high tickover ,try and get your tickover as close to 1500 as you can


lower the tickover after the test tho

[Edited on 4/6/05 by OX]