View Full Version : failed mot - emissions help
novamadman
24-08-06, 09:27 PM
failed mot - emissions - co2 was fine, hydrocarbonds were 3600 ! suposed to be 1200 or below
re test on saturday morning - need help quick how the hell am i going to get them down
its a 1200 with head done, ast2 cam, weber 32/34, ticks over like a bag of bottles
anyone help?
cheers shane
matt1chelski
24-08-06, 09:34 PM
Plugs and leads?
i dont have a clue what hydrocarbonds are could try some redex down the carb then after adjust the mixture so it runs a little lean
this just a guess if its wrong i am sure some one will say
nova~norm
24-08-06, 09:41 PM
get carbs set up? timing out? Plugs leads?
doug_sri
24-08-06, 10:36 PM
mine failed this, 20xe with cams and power cap and all that. in the end i couldnt get it down and spoke to another mechanic and he straight away said timing altho my c02 was a bit high as well. put the standard cams back in and it was spot on
stv-b16a
25-08-06, 12:29 AM
like your mechanic said its the timing not the cams.
stv-b16a
25-08-06, 12:29 AM
get it set-up properly. preffaribly on a rolling road.
novamadman
25-08-06, 12:36 AM
the car has had all new everything inc. plugs and leads, carb recently serviced new seals gaskets e.t.c, new inlet manifold, runs fine its just lumpy with the cam,
hydrocarbons = unburnt fuel parts per million
the car is setup fine i think its due to the fact shes to well setup that the hydrocarbons are his high. Going tommorrow morning to a guy who has the machine, will footer and mixture and timing there see what we can do, failing that either cam change, pierburg 2e3 or both :(
shane
stv-b16a
25-08-06, 12:51 AM
a new carb doesnt mean its been set up properly. define lumpy- doesnt idle well, feels jittery when proggresing through the rev range. what cam are you running. theres no such thing as too well set-up
stv
novamadman
25-08-06, 12:55 AM
a new carb doesnt mean its been set up properly. define lumpy- doesnt idle well, feels jittery when proggresing through the rev range. what cam are you running. theres no such thing as too well set-up
stv
lumpy means lumpy, not jittry going through rev range, its an ast2
what i mean by too well setup is its set to go as hard as it can/well as it can which probably isnt helping the emissions
shane
stv-b16a
25-08-06, 12:59 AM
well then define lumpy?
novamadman
25-08-06, 01:07 AM
well then define lumpy?
off the point but
basically a rough idle, not level or steady
so your saying if a car is cammed and runs lumpy it wont rev clean........?
lets try and go back on topic
shane
stv-b16a
25-08-06, 01:13 AM
i didnt mean to sound like a cheeky bastid just wanted to know what you meant by lumpy.
stv-b16a
25-08-06, 01:16 AM
what cam are you running?
novamadman
25-08-06, 01:25 AM
what cam are you running?
didnt think that at all
for the 3rd time in the thread - kent ast2
going to be now, goodnight
shane
stv-b16a
25-08-06, 02:22 AM
lol think ive had a few too many sherries lol
goodnight.
stv
might be a long shot mate, but here goes!!
has the head been skimmed, if so then have you adjusted the cam timing as this changes with head skimming, i worked it out at about 1 tooth backwards for cam timing of 103 degrees for 35 thou skim, as my racing nova had an ast2 cam in it, and i didnt change the cam timing to compensate head skim (dough), also might help hydrocarbons by adding somekind of oxygenate fuel, for example an octane booster might help a little bit?? dunno m8,the only reason ur getting hydrocarbons high readings is because fuel not burning fully, maybe the ignition, but oxygenated fuels burn alot cleaner in engines, hope this helps mate
novamadman
26-08-06, 12:35 PM
failed again today YAYYYYYYYY!!
with a standard inlet manifold and pierburg 2e3
is it just the cam?
shane
Can you not just knock down the fuel/air mix.
novamadman
26-08-06, 01:42 PM
Can you not just knock down the fuel/air mix.
believe me mate i tried with the weber and nw with the pierburg, i got the c0 set with weber but ppm went thru the roof, now with poerburg ive brought the ppm down a bit and c0 up a bit, i think if the cam was changed for mot it would sort it
shane
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