Another Smog Fail

[peetiewonder]

So i went to smog today, had a feeling i wouldnt like the results but had to so i could get registration. here's the results.

15mph
%CO Meas 14.4
%O2 Meas .5
HC Max 118 Meas 136
CO Max .75 Meas .66
NO Max 799 Meas 3762 (Gross Polluter)

25mph
%CO Meas 15.0
%O2 Meas .1
HC Max 93 Meas 64
CO Max .63 Meas .39
NO Max 738 Meas 1315 (Fail)

Other notes:

Car
91 240sx coupe KA24DE

Only mod on the car is HKS Hi-Power exhaust (2.5" catback) everything else is stock. ran on 91octane fuel.

Found out my timing is set at 26 degrees = autofail
and
My CEL came ond during the test:eek::eek::eek:

Now from reading the other threads, i know that the EGR is probably responsible for the high NO readings but what woudl be responsible for my HC numbers? Also im new to this i'm going to search on a tut for setting my timing but if u know of a good one please post for me. I'm going to pull my ecu codes tomorow or thursday, but i am guessing 32 and 34 because i have been getting those on and off.

Also does anyone think seafoam would help me out at all? any tips appreciated thanks.

[FRoSt415]

replace the air filter if its dirty and the maf sensor with some carb cleaner and a towel. the high NOx is very bad it point to the EGR or CAt, if you have been driving it for at least two years u might have burned up ur cat and made it empty and worthless. check the EGR if it is hooked up correctly then check for vaccum going into the EGR. then Clean it if you can. then to check to see if your CAt is ok get something to hit it with like a stick and check if it sounds hollow. And Adjust that timing to within 10 degrees and get a pretest. Then post up numbers from pretest and see if we can solve it.

[peetiewonder]

shouldnt the timing be within 2 degrees of 20? ill check the other stuff out tonight or tomorow.

[Pacman]

Check the vacuum line from the EGR valve to the transducer is not corroded. I bet you it is. The one I'm talking about 90* line. Ones that is working, have it pretested. See how your numbers looks. Check to see what code you have. Where your timing is at I believe it can cause a higher HC since its way to advanced to let the full mixture to burn. Set timing to 20* +/- 2*. Check the FSM for proper base timing adjustment procedure. Once you EGR is working (and cleaned, remove and clean the carbon build-up), retest. Your cat could be shot. Make sure the pulse air injection is properly working as well.

[peetiewonder]

is the 90 degree line a hard line or a soft vacuum line?

[FrankDukes]

20*Degrees BTDC is stock on the KA24de and Retarding it will help with smog.

You need to set your Timing at 18 or 19* degrees BTDC.

High NOX is also can be a result that the guy doing the test isn't shifting correctly.

Previously I failed smog with (1108 NOX ) measured. The guy ran at 15mph 1st gear and shifted at 1,100 rpm to 25mph. What a dumbass.

My new friend and smog person, ran the car at 15mph and shifted at 2,900rpm and just by doing this there was more Vacume and it opened the EGR, and I measured only (85 NOX)..

Basically my smog person didn't do anything different except:

1. Put that BIG Ole fan to blow in front of the car
2. Kept the car running while i was parked there, (to warm up the cat) Once you turn off your car at the smog shop, the cat cools very fast. You want to drive it around and don't turn it off even while at the smog place.
3. He shifted the car late, to get high revs to open up the EGR

HC is hydrocarbon, this could just be due to bad timing, spark, and combustion chamber not combusting stoichiometricly.



Please tell me what was the RPM

[yukon]

Do you know why retarding helps with smog? if it sparks later, dont you burn less fuel and have more unburned hydrocarbons. im asking because i dont know.

[fast-datsun]

fresh tune up, new cat and clean working EGR will do it...

[peetiewonder]

the guy who smogged me didnt shift it at all, he ran 15 and 25 both in first gear.

[FRoSt415]

What a Retard hes suppose to run it in second gear. What have u done to the car now? Have you gotten your pretest for retake?

[peetiewonder]

no not yet. still gotta fix the egr

[miklos]

Make sure the pulse air injection is properly working as well.
How does the PAIR or AIV affect this? The air injection should only work during warmup of the engine

[xavier240]

glad im in florida i couldnt live with having to do that. gl 2 u guys.

[handinpants]

don't forget to change the oil,

[Pacman]

How does the PAIR or AIV affect this? The air injection should only work during warmup of the engine

Converter light off. But what do I know, I only do this car thing for a career.