emissions failure

[SoddyDaisyFJ]

I went to get my 83 fj-60 tested again today for the Hamilton County Tenn. smog test, and did not pass.

Results:
Hc.
reading-1291
limit-220
Co.
reading- 0.16 (was at 1.74)
limit- 1.2

The Hc. reading is very odd, because I tested three weeks ago and that # was at 815. after which, I repaired the following:
-new Napa air pump (the oem unit was gutted and about to seize.)
-checked/cleaned pcv and it was in working order according to the emissions manual
-adjusted the valve lash to spec
-timed it to 7* past top dead center (it was at about 14*)
-did a sea foam treatment (in the carb)
-new plugs
-compression test ( all were at 145-150 psi, except cyl. 3&4 which read 130-135. im not burning any coolant or oil
-new air filter
-1 bottle of "guaranteed to pass" before the test

I have a few ideas on what may have caused the strange #s.
A. after putting on the new smog pump, the air flow blew countless years of suit (there is alot of it) from the egr hoses and valves into the cat.
B. seafoam treatment worked too well at breaking up the carbon
C. my timing adjustment negatively affected the fuel burn
D. faulty egr system.

If anyone has any ides as to why the Hc. went up, and more importantly how to lower them, please chime in. I plan on a new cat, will this be a good plan? im going to go do some homework so i will be on later tonight.

 

[NocalFJ60]

The test done at idle? Got a oxygen measurement? Have you tested the air injection system? Does it idle smooth? My first guess if it is at idle is a vacuum leak or the idle mixture screw is set too lean.

 

[SoddyDaisyFJ]

yea, test is done at idle, and the air pump is fully functional. i have it idling smoothly at 800rpm. i will check vac leak next. and i did not get an 02 reading.

 

[NocalFJ60]

Have you adjusted the idle mixture or do you still have the plug over the idle mixture screw? The idle speed in the FSM is 650 rpm. You have a vacuum gauge? Take a reading in the intake. The air pump can be fully fuctional but if the ABV is bad then is just dumps the air straight back to the air cleaner. Follow the hose coming of the ABV back to air cleaner and make sure no air is there. I would make sure you don't have a intake leak (spray bottle with water around carb and see if it runs rough) then do the lean drop method to adjust the idle mixture and idle speed.

 

[rchalmers3]

The high HC's and low CO may be related. HC's are unburnt fuel passing out of the engine. If the A/F ratio is too lean, you will have a problem getting passing numbers.
Try this: Set the CO to about .5 or .75 ppm and re-check HC emissions. Also, do a cat test to verify Catalytic Converter efficiency, 'cause your numbers are pretty high in general.
Oxy emissions are important, as well as CO2. It's a benefit to us if you post all the gasses when describing a failure.

Rick

 

[SoddyDaisyFJ]

thank yall for the replies. i have adjusted the carb with the lean drop method in the fsm, but i left it lean. I will go back and adjust it again. along with vacuum testing the abv. i have a mighty vac

the print out it gave me did not include O2, but my Co2 was at 7.82 %
besides the infrared thermometer, how would yall suggest checking the cat?

 

[Dynosoar]

Go for a good highway run and get the cat nice and hot before the test.

Dynosoar

 

[rchalmers3]

An easy way to test the cat requires access to a 4 gas bench. Simply run the truck starting with a Cool cat and watch the gas numbers as the Cat heats up. When the Cat fires the numbers will fall dramatically. Bad Cat, little improvement of numbers.

Rick

 

[rchalmers3]

CO2 was low, but no surprise there as the HC's are high. You should see CO2 around 14% when all is well.

Rick

 

[SoddyDaisyFJ]

what i plan on doing is readjusting the idle mix, checking some more stuff for vac leaks, and taking it down to the local muffler shop and have them look at the cat. hopefully all goes well, but i will post when i find out

 

[flybynight]

I will second the hot cat as well. During first test the tech let it sit for too long. Even at idle the cat can cool off enough to loose efficiency.

Had very similar results, second test made sure it was good and hot for the test and passed with no issues.

 

[SoddyDaisyFJ]

its good to hear that you made it pass with those numbers, i have been been praying that i can do something to keep the fj. But while waiting in line for the test, i was revving up, and keeping the engine hot. im going to go out and richen the mix and bring it to the local maxi, i will let yall know how it goes.

while im here, is there a good way besides "guaranteed to pass" and bribery to cheat a test. i have heard of running air pump hoses to dilute the exhaust. Is there anyone that can elaborate?

 

[flybynight]

Do you have test only stations there? If you can take it to a mechanic for the test they usually can tweak the truck on the spot. Doesn't cost much extra if at all. With in reason.

Norcal has much knowledge in this area, and has contributed to a lot of threads. Be sure to search a lot.