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@CycloSteve - glad you said it was a dead link, I looked for a bit & it was annoying AF. Thx!
Fail Colorado Emissions Test Again (1 Viewer)
- Thread starter landtoy80
- Start date
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inkpot
SILVER Star
So,,,, someone re-invented SeaFoam, again??
Just went through this with my 1994. Colorado lowered the limits from my last test and as a result I failed, just barely. I had slightly high HC and my NoX was like a 4.8 however I only failed from the Nox. The problem is the only way to lower NoX is to reduce combustion temperature. This is accomplished through retarding the timing or adding exhaust gas back into combustion. OR burning it out at the catalytic converter. Most all of the guaranteed to pass formulas work by leaning out the engine and reducing HC, however in running the engine leaner you raise the NoX. Conversely if you retard the timing you will lower the NoX but you will increase the HC.
I would suggest verifying your EGR is clean and functioning, verify there is no vacuum leaks. Keep timing at the factory setting, and replace the old tired cats. When Colorado lowers the acceptable passing limits again we are screwed, Even with everything in perfect running condition, perfectly clean, good fuel, brand new cats, I was only able to get the NoX down to a 3.8 with a fail at 4. I have a feeling in two years when I have to do another E test, it may be time to buy some property In Park County. It will probably be cheaper than trying to get the 80 to pass unrealistic emission standards.
I would suggest verifying your EGR is clean and functioning, verify there is no vacuum leaks. Keep timing at the factory setting, and replace the old tired cats. When Colorado lowers the acceptable passing limits again we are screwed, Even with everything in perfect running condition, perfectly clean, good fuel, brand new cats, I was only able to get the NoX down to a 3.8 with a fail at 4. I have a feeling in two years when I have to do another E test, it may be time to buy some property In Park County. It will probably be cheaper than trying to get the 80 to pass unrealistic emission standards.
Edit: I meant to type CO instead of HC. I had a slightly high CO and failed on Nox, and if you lean the engine out you will lower your CO levels, raising your NoX.
Also in my repairs I replace the O2 sensors, however they where due, so no loss there,
Also in my repairs I replace the O2 sensors, however they where due, so no loss there,
I hope that garbage doesn't makes it way down here to the springs though...
I'm not sure if I still have my old throttle cable but if I do you are welcome to it...it wasn't super smooth but would let the throttle body close to idle no problem. I won't be able to check until Christmas though....
NEVER!!... Or I'll move farther south. (Turkey Creek area).
Seriously tho, I'll give any cruiser owner my address. Y'all are more than welcome to use it to claim residency out from behind Colorado's iron curtain.
I'll claim we're "roommates" if ever questioned.
I'll claim we're "roommates" if ever questioned.
- Thread starter
- #30
I removed the rear driveshaft and got the throttle cable to work freely.
Got on the dino and to my surprise the rear wheels were turning during the test.
The front and rear dino rollers are connected. So much for removing a driveshaft.
Might of worked if they put me on the single roller.
Failed again but it got better.
Passed with CO and NOx got a little better.
Second Test
HC 1.0070 pass
CO 13.23273 pass
NOx 5.3084 FAIL
CO2 675.2536
First Test
HC 1.4107 pass limit is 2
CO 21.0195 FAIL limit is 20
NOx 5.541 FAIL limit is 4
CO2 654.2573 no limit on test
No one sells G-Oil any more in CO.
Got on the dino and to my surprise the rear wheels were turning during the test.
The front and rear dino rollers are connected. So much for removing a driveshaft.
Might of worked if they put me on the single roller.
Failed again but it got better.
Passed with CO and NOx got a little better.
Second Test
HC 1.0070 pass
CO 13.23273 pass
NOx 5.3084 FAIL
CO2 675.2536
First Test
HC 1.4107 pass limit is 2
CO 21.0195 FAIL limit is 20
NOx 5.541 FAIL limit is 4
CO2 654.2573 no limit on test
No one sells G-Oil any more in CO.
- Thread starter
- #31
Took another test and FAILED.
Removed the air filter to see if the dirty looking washable air filter is plugged, must be clean as it didn't change results much.
Installed the new used throttle cable.
Ran with the ECT on.
First run with OD off, second with OD on. The test doesn't show results from first and second try (you get 2 runs on dino if you fail).
No Iso Heet in tank. Shell 85 Octane gas.
NOx got slightly worse but about the same as the other tests.
HC and CO both went down.
If I have time I will soak the Cats and O2's in citric and oxalic acid like I did 2 years ago.
Third Test
HC 0.9345 pass
CO 12.9422 pass
NOx 5.5301 FAIL
Second Test
HC 1.0070 pass
CO 13.23273 pass
CO2 675.2536
NOx 5.3084 FAIL
First Test
HC 1.4107 pass limit is 2
CO 21.0195 FAIL limit is 20
CO2 654.2573 no limit on test
NOx 5.541 FAIL limit is 4
My passed test 2 years ago after doing a Cat and O2 citric and oxalic soak.
I also used G-Oil (vegetable bases oil) in motor and 3 bottles of Heet in tank.
HC 0.5986
CO 9.9442
CO2 555.035
Nox 2.8966
Can no longer find G-Oil locally and its $$$ online so I hope the cat bath works.
All else fails, I will have to buy new O2's and or Cats. I did have a Code 25 26 from some time ago.
Removed the air filter to see if the dirty looking washable air filter is plugged, must be clean as it didn't change results much.
Installed the new used throttle cable.
Ran with the ECT on.
First run with OD off, second with OD on. The test doesn't show results from first and second try (you get 2 runs on dino if you fail).
No Iso Heet in tank. Shell 85 Octane gas.
NOx got slightly worse but about the same as the other tests.
HC and CO both went down.
If I have time I will soak the Cats and O2's in citric and oxalic acid like I did 2 years ago.
Third Test
HC 0.9345 pass
CO 12.9422 pass
NOx 5.5301 FAIL
Second Test
HC 1.0070 pass
CO 13.23273 pass
CO2 675.2536
NOx 5.3084 FAIL
First Test
HC 1.4107 pass limit is 2
CO 21.0195 FAIL limit is 20
CO2 654.2573 no limit on test
NOx 5.541 FAIL limit is 4
My passed test 2 years ago after doing a Cat and O2 citric and oxalic soak.
I also used G-Oil (vegetable bases oil) in motor and 3 bottles of Heet in tank.
HC 0.5986
CO 9.9442
CO2 555.035
Nox 2.8966
Can no longer find G-Oil locally and its $$$ online so I hope the cat bath works.
All else fails, I will have to buy new O2's and or Cats. I did have a Code 25 26 from some time ago.
- Thread starter
- #32
Cleaning the cats reduced the NOx (still too high) but CO has gone up and now too high.
HC 0.8458 max 2
CO 21.5061 max 20
CO2 774.7346
NOx 4.5651 max 4
Don't understand why CO when up other than it was very cold out, about 10 deg at test time. Other tests were in 40's 50's.
The oil is very dirty at 1700 mi. The PCV sucks up lots of oil vapor from my high mileage blowby.
Now to find some NoSmoke/Biodegradable oil for testing.
Last time it took cat cleaning, G-Oil (vegy based) and 3 bottles of IsoHeet to pass.
HC 0.8458 max 2
CO 21.5061 max 20
CO2 774.7346
NOx 4.5651 max 4
Don't understand why CO when up other than it was very cold out, about 10 deg at test time. Other tests were in 40's 50's.
The oil is very dirty at 1700 mi. The PCV sucks up lots of oil vapor from my high mileage blowby.
Now to find some NoSmoke/Biodegradable oil for testing.
Last time it took cat cleaning, G-Oil (vegy based) and 3 bottles of IsoHeet to pass.
Your running shell 85 octane gas?
I would run 91 or higher octane for testing...
I would run 91 or higher octane for testing...
- Thread starter
- #34
Changed the oil to canola oil, couldn't find cost effective veggie based so I made my own.
Almost passed.
HC 0.8449 pass
CO 13.6570 pass
CO2 691.0228
NOx 4.2559 FAIL 4.0 max
Just for fun I mixed up some E85 with 91 octane and failed, numbers got worse.
I also cleaned off the carbon from the cap and installed new spark plugs that were not that bad looking and had about 15,0000 mi on them.
HC 0.9159
CO 19.6306
CO2 693.0502
NOx 4.3947 FAIL 4 max.
Almost passed.
HC 0.8449 pass
CO 13.6570 pass
CO2 691.0228
NOx 4.2559 FAIL 4.0 max
Just for fun I mixed up some E85 with 91 octane and failed, numbers got worse.
I also cleaned off the carbon from the cap and installed new spark plugs that were not that bad looking and had about 15,0000 mi on them.
HC 0.9159
CO 19.6306
CO2 693.0502
NOx 4.3947 FAIL 4 max.
You should be running 87 in Colorado. 91 is not necessary and could be why you have high CO. Typically CO is from unburned fuel. The NOx is typically lean condition from timing or carbon deposits or likely EGR, knowing our trucks. Yes, you can have both lean condition and unburned fuel in the same test.
They should have given you a second paper with some graphs. Post that up. Are your numbers high during accel, decel, or cruise? That will help you figure out what needs fixed.
Set your timing back to 7* and leave it alone, maybe 10* if you're frisky, and just run 87 and a can of sea foam every 6 months. And buy ethanol free gas when you can, especially in the mountain towns.
Edit: I don't know if it ECUs are as smart as newer. But I still think they learn the fuel and driving conditions. So mixing fuel and changing octanes and what not could be part of the problem. Also, the truck will run richer with cold outside air temps. Wait for a more moderate day.
They should have given you a second paper with some graphs. Post that up. Are your numbers high during accel, decel, or cruise? That will help you figure out what needs fixed.
Set your timing back to 7* and leave it alone, maybe 10* if you're frisky, and just run 87 and a can of sea foam every 6 months. And buy ethanol free gas when you can, especially in the mountain towns.
Edit: I don't know if it ECUs are as smart as newer. But I still think they learn the fuel and driving conditions. So mixing fuel and changing octanes and what not could be part of the problem. Also, the truck will run richer with cold outside air temps. Wait for a more moderate day.
I just want to state for the record - if you DO have codes, the ECU will retard the timing. The 93-94 ecu is smart enough to do that, not quite smart enough to give you enough information to solve the problem.
replacing the CEL light isn't so hard as to not be worth it at this point. Since you might be looking at new cats, etc.
There was a recall for 93-94 o2 sensors. Might be able to get a set for free at the dealership. Which means something as the 93-94 sensors are Different and Very Expensive.
replacing the CEL light isn't so hard as to not be worth it at this point. Since you might be looking at new cats, etc.
There was a recall for 93-94 o2 sensors. Might be able to get a set for free at the dealership. Which means something as the 93-94 sensors are Different and Very Expensive.
- Thread starter
- #37
Recall O2 were replaced long ago.
Now that I am sure my 80 doesn't like ethanol, I found a station that sells 100 pure ethanol free gasoline. I will give that a try just to see what happens.
Maybe I will find a full time befor the end of month so I can afford new cats and or O2's if straight gas doesn't work.
Now that I am sure my 80 doesn't like ethanol, I found a station that sells 100 pure ethanol free gasoline. I will give that a try just to see what happens.
Maybe I will find a full time befor the end of month so I can afford new cats and or O2's if straight gas doesn't work.
I wasn't aware retarding the timing was possible with a direct drive distributor cap like the FZJ80 has. What mechanism retards the timing via the ECU?
Reading this thread has really got me down! I'm thankful that mine passed CO smog with the oil I had in it and 85 octane. Not sure where in the front range you are- I've noticed a few places around Denver that have ethanol-free fuel. Someone in the local club recommended this app/website for tracking ethanol-free stations:
Ethanol-free gas stations in the U.S. and Canada
pure-gas.org (if the link text doesn't show)
Ethanol-free gas stations in the U.S. and Canada
pure-gas.org (if the link text doesn't show)
- Joined
- Sep 17, 2003
- Threads
- 64
- Messages
- 4,427
- Location
- Sunnyvale, CA
- Website
- www.george4wd.taskled.com
??? The coil is fired by the ECU via the igniter. That's means the ECU can do whatever it wants with the timing (to the limit of the rotor sweep)... We don't have points in our 80's...
Have you ever looked at the rotor of an 80 inside the distributor cap? It has a LOT of rotational contact area with each spark plug contact point - this allows quite a bit of timing variation (when the coil is fired) and still have the rotor touching the appropriate spark plug contact point.
cheers,
george.
