KA smog fail. Help please.

[Nis13mo]

Guys,

I tried smogging my KA and it failed. Does any of you have any tip on what I should mess with to get the engine to pass?



Looks like I'm failing during idle. Things I did before the test:

yes-i took it in when hot (running for about 20+ minutes)yes-oil was change about 3 weeks agoyes-idle adjusting value was cleanedyes-new spark plugs/wires (4-5 months)yes-arco preminum gas I appreciate all your help.

Thanks.

[480sx]

Your just barely failing. What about your intake filter, cap and rotor? Might as well replace them while your at it. Did you run a can of injector cleaner through the tank?

Whens the last time youv replaced your O2 sensor? You probably dont NEED one but it would help, and it would give you better fuel econ.

[Nis13mo]

I don't recall having ever replaced the o2 sensor. Thanks for the tips. I'll try them and see what happens.

[xekushnr]

Mods, if any? What year is it?

[Nis13mo]

Mods, if any? What year is it?

No mods. Can't afford them at the moment.

It's a '93.

[Nis13mo]

Do you guys think lowering the idle from 800 rpm to around 600-700 will help?

Thanks.

[sormeroid]

why dont they do this in other states?

[IHeartRPS13]

What octane are you running? I ran 91 when i smog mine

[Nis13mo]

What octane are you running? I ran 91 when i smog mine

I ran 91 also..

[MJDalton]

Here look this over maybe it will help :

just general specs,

first the gases"HC" is your hydro carbons. organic compound that contains carbon and hydrogen"CO" carbon monoxide. incomplete combustion of hydrocarbon(fuel) and oxygen. Colorless, and odorless"NOx" nitrogen oxides, nitrogen and oxygen produced at higher combustion temperatures"CO2" carbon dioxide colorless, odorless, heavier than air"O2" oxygen

a exhaust gas analyze or the emissions test should give you your read out for the gases at what your truck is currently producing

with good combustionCO2 should be about 14-16%. increases with the efficiency of combustionCO and O2 should be low and equalHC Low level is bestNOx should be just lower than max at your are fuel ratio of 14.7:1

High CO= Rich condition, CO is partially burned fuelCauses-High fuel pressure-Leaky injectors-faulty temp sensor-thermostat stuck open-clogged air filter-sticking choke-high float level-leaking accelerator pump or power valve-charcoal canister full, fuel to topped off, faulty purge solenoid-Fuel in the crankcase

low CO/high O2 =Lean condition-to little fuel-to much air-low fuel pressure-plugged fuel filter-bad fuel pump-plugged injectors-vacuum leaks-low float level;-plugged or wrong jets

High HC= incomplete combustion-bad ignition, coil, plugs, wires, cap, rotor-over advanced timing-low compression-stuck EGR

Low O2-Rich condition. still burnable fuel mixture

High NOx-combustion temps over 2,000*'s-thermostatic air cleaner stuck closed-higher compression-to far advanced timing-low oil level-cooling problems, getting to hot. thermostats', temp sensor, radiator......-to low of octane- Faulty EGR-Vacuum leak-low fuel pressure-wrong heat range of spark plug-cat converter junk

CO2- before engine warm up, when still in closed loop, should be 10-13%after warm up, should be 14-16%if it doesn't increase catalytic converter is not functioning properlyCO2 below 10% indicates extremely dirty exhaust and/or cat converter isn't operating

High O2 +high CO + high HC=misfire do to over rich mixturehigh O2 +low CO + high HC= lean misfireHigh O2 +Normal CO +high HC= miss do to mechanical or ignition problemsHigh O2 + normal CO + normal HC= O2 getting into exhaust via air pump, or exhaust leak

if HC goes up, O2 should go upIf HC goes down, O2 should go down

if CO goes down, O2 should goes upIf CO goes up, O2 should go down

CO2 should be highest at the engines most efficient spotC02 goes down if anything else moves.

Good Luck Mike

[Nis13mo]

These are some really good informations. Thank you.