My Continuous SMOG and Emissions Problems

[sacfj60]

Did you give it a tune up before the test?
Drive it on the freeway for 20 minutes right before the test?
High HC is high hydrocarbons. There’s unburned fuel ending up in the exhaust pipe. Engine is running too rich.
Just a dirty air cleaner filter can cause high HC because engine isn’t getting enough air (as an example).

drove it for over 20 minutes before I took it in but i don't drive it often enough and it sat for a while until they got to it. . threw some good gas and sea foam in and drove it about 40 miles this week so that may be the issue. brand new air filter. no tune up before hand. the timing issue seems strange. I have not set it in years and never had an issue with it on a smog check. if i change the timing to 7 will that negatively affect the outcome?

 

[OSS]

Your %O2 is too low. Both values (at 15 and 25 mph) should be in the twos. (Mine always were). This is a reflection of something not working right with the air injection system.
This ai failure is reflected in your failed CO test. That value is way too high. Mine were always 0.1% for every test for 38 years. Engine with 285,000 miles on it.

Test the air injection system.

7° timing will only help if yours was at 12°

 

[sacfj60]

Your %O2 is too low. Both values (at 15 and 25 mph) should be in the twos. (Mine always were). This is a reflection of something not working right with the air injection system.
This ai failure is reflected in your failed CO test. That value is way too high. Mine were always 0.1% for every test for 38 years. Engine with 285,000 miles on it.

Test the air injection system.

7° timing will only help if yours was at 12°

ok, thanks as always. not sure how to test the system or all that is involved with that but I will look into it. as for the timing. it is at 12. will 7 make any difference with my numbers or is that a separate issue?

 

[OSS]

Yes-
Timing advanced past spec will create more emissions. 12° is bad. 7° is good.
Attached is the 2F emissions manual. It has testing procedures for everything.

 

[Pin_Head]

If it hasn’t run in a few years, the mechanical advance in the distributor may be stuck. Lube it and turn the rotor back and forth to free it up. The air vents for the slow jets and emulsion tubes may be plugged. Try the Oklahoma carb rebuild: Spray carb cleaner all over in the carb, let it sit 5 minutes, then start it up, rev it to 3,000 RPM and then hand choke it until it almost dies. Repeat a couple of times.

 

[sacfj60]

If it hasn’t run in a few years, the mechanical advance in the distributor may be stuck. Lube it and turn the rotor back and forth to free it up. The air vents for the slow jets and emulsion tubes may be plugged. Try the Oklahoma carb rebuild: Spray carb cleaner all over in the carb, let it sit 5 minutes, then start it up, rev it to 3,000 RPM and then hand choke it until it almost dies. Repeat a couple of times.

cool. thanks for that. I do drive it a few times a month but that isn't enough apparently. I guess the first thing is to fix the timing, run it hot on the freeway and see how that helps and then go from there. the air intake seemed to be working although it wasn't very strong. this is my 10th smog check with this thing and it is always something different. i always pass but this time the usual numbers are not the culprits.

 

[Pin_Head]

cool. thanks for that. I do drive it a few times a month but that isn't enough apparently. I guess the first thing is to fix the timing, run it hot on the freeway and see how that helps and then go from there. the air intake seemed to be working although it wasn't very strong. this is my 10th smog check with this thing and it is always something different. i always pass but this time the usual numbers are not the culprits.

Air intake? What is that?
I was referring to the tiny air metering holes in the slow jet and emulsion tube that mix air with fuel. If they are clogged, it will run very rich. It is hard to know if they are open without disassembling the carb and checking them, hence it is easier to just treat them as if they were clogged with the spray cleaner and pulling fuel out of them to unblock them.

 

[sacfj60]

Air intake? What is that?
I was referring to the tiny air metering holes in the slow jet and emulsion tube that mix air with fuel. If they are clogged, it will run very rich. It is hard to know if they are open without disassembling the carb and checking them, hence it is easier to just treat them as if they were clogged with the spray cleaner and pulling fuel out of them to unblock them.

oh right. I tested the air injection system i.e. the air cleaner hoses. i have been running seafoam in the system periodically. which i hoped would keep it clean but maybe it just stirred up a lot of sediment. is there a particular carb spray that is recommended? I am going to get the timing set and then try that before a long drive and a retest.

 

[Pin_Head]

Any spray can that says “carb cleaner” on it will do. Fuel additives don’t clean out air metering ports because they don’t normally encounter fuel until you pull a strong vacuum on them by revving the engine and then covering the air intake at the top.
Good luck.

 

[sacfj60]

Forgot to mention I passed a a few weeks ago. stoked!