So I went to get the car tested today, but it failed due to too high of hydrocarbon count during the fast idle test (it is twice the limit). I took the car home, turned the fuel/air mixture way down, checked the timing, adjusted the curb idle for compensation and it didn't change at all.
The only emissions equipment I have removed from the car is the EGR valve and its tube, but I don't believe it was doing anything for the emissions the first time I got the car tested because it was so plugged up.
I can't understand why the car is failing as if it is running way to rich.
Well I adjusted the fuel/air mixture screw all the way in, then backed it out two turns and fiddled with it at that setting until the motor ran smooth. Then I adjusted the curb idle until it was idling around 700 RPM and left it there.
Good news is, the sputtering/putting at the tail pipe went away and it sounds really healthy now. The knock I posted in a previous thread has lessened.
I went to get the car tested one more time today but they had just shut the computer down, so I will be going back Wednesday to get it tested and see how she goes. Wish me luck!
How is the cat./conv.? (if applicable)
Bill
Luck!
High HC's mean unburned fuel (too rich or a misfire will do the same thing). I had an old Baja bug that would not pass due to a modified intake and carb putting the HC's way over the limit. About 2 gallons of methanol in the tank and a trip back to the sniffer took care of that.
Quote from: CHEAPRACER on August 18, 2008, 10:06:32 PM
High HC's mean unburned fuel (too rich or a misfire will do the same thing). I had an old Baja bug that would not pass due to a modified intake and carb putting the HC's way over the limit. About 2 gallons of methanol in the tank and a trip back to the sniffer took care of that.
IIRC: Don't they "sniff" for that now and fail you for having it in the test?
Bill
The car passed with AMAZING results last year, I don't see how all of the readings have nearly tripled since though!
The cat is on the car...or at least the shell is....(it's been like that since the mid 80s and always passed, even when burning oil prior to the rebuild)
hey dave i put on a rebuilt carb that was bench tested and only adj. the idle speed and passed smog in ca. it runs 50% cleaner than the limits.my old carb was leaking a small amount of fuel in the intake i guess and it would funk the test.i have a 77 2.3 with auto. chris
Pintony, that is exactly what I was forgetting!
A mixture that is too rich will give high CO generally. If you lean it out too much, you will have 'lean misfire' and high HC. One way to think of it is if the fuel ignites, but runs out of oxygen, you get carbon monoxide CO instead of carbon dioxide co2 that you should get. If the fuel does not ignite, then the exhaust will have hydrocarbons (fuel) in it.
Well I got a retest done again today.
This time it passed the HC for both idle and the 2500 RPM tests, but failed for CO. CO for the idle test was at 7.26 and the 2500RPM test it was at 7.1 with the limit being 3.00.
So should I lean out the mixture and raise the curb idle slightly?
A long time ago when I lived in California we had to pass the state test.
Here is what I would do when ever it failed.
1) Adjust the idle mixture screw. Start with the screw backed off about 6 turns. Slowly screw it in until it runs smooth. Keep screwing it in until the it runs rough and RPMs drop. Now back it off until it runs smooth. This is the optimum setting for your engine.
2) Check your timing and note the location for future reference.
3) Now we screw everything up to get it to pass emissions.
4) Screw the idle mixture screw in until it start to slow down RPM's and run slightly rough. Leave it there.
5) Retard your timing 4 degrees.
6) Cut your distributor vacuum advance line in the middle. Install a solid round rod to block the vacuum. Put back togther.
7) Yes, it will run poorly. But it should pass.
8) If you pass, return everything where you had it. Install a junction tube in place of the solid rod for the distributor vacuum line.
Quote from: 77turbopinto on August 18, 2008, 10:14:49 PM
IIRC: Don't they "sniff" for that now and fail you for having it in the test?
Bill
I did that over 20 years ago, not sure now.
Starliner, I will try doing that after I have the car checked again tomorrow!
Any idea how far out/in the curb idle screw should be? Should I just get the engine to idle rough after adjusting mixture then compensate and leave it slightly rough with the curb idle adjustment?
I tore apart the carb and adjusted the float today, it was off by 1/8". I also cut a new gasket for the manifold to spacer. The tailpipe doesn't stink at all, and it runs great. I will have to see if my adjustments are good to go tomorrow after testing though.
Well the car doesn't seem to want to drop in CO (carbon monoxide) for either the idle or the cruise test.
I had the car tested with the timing retarded and the mixture leaned and it passed the CO test on the idle but not the cruise, and failed teh hydro carbon for both.
I'm ready to give up on this and just park the car. Looks like I'll be driving my '07 Saturn now. :'(
How much acetone should I add to a 1/2 full tank so I pass emissions??