Hi Everyone,
>
> This is my first post to this group so bare with me if you can.
>
> I have an emissions problem with my 1982 Toyota pickup truck that I
> cannot diagnose. My Smog numbers:
>
> Idle RPM (995RPM)
> MAX HC MY HC MAX CO MY CO CO2% O2%
> 250ppm 21ppm 2.0 .01 13.2% 2.9
>
> 2500 RPM (2488RPM)
> MAX HC MY HC MAX CO MY CO CO2% O2%
> 200 213(FAIL) 2.0 1.0 14.5 1.0
>
> Now this was my third pretest, my numbers were higher for my 2
> original pretest, I got the numbers down by: Cleaning out EGR valve
> which was clogged, Tuneup(sparkplugs, spark plug wires, oil change,
> fuel filter, air filter), noticed my O2 sensor was not hooked up,
> bought a new one replacing original 02 sensor, noticed I had a exhaust
> manifold leak and had that fixed, fixed a broken BVSV valve. New
> catalytic converter. The numbers for HC rise past the limit as the
> smog technician steps on the gas, I am at a loss as to why my numbers
> are so low at IDLE then at 2500RPM. I am thinking maybe it is the
> carberator, can anybody with experience with this problem diagnose
> this for me, Thanks in advance.
MDTECH wrote: A rule of thumb, HC are mechanical, while CO is fuel problem, exception is a lean condition can create a missfire where HC's will go way up, but CO will be way down. I'd adjust the valves (.008/.012 hot) and make sure you have a working vacuum advance, I mean both diaphrams and base timing is set to specs. If all of that fails, and I think it will pass after that, you can lower the float level too. Keep it in specs, just the lower end of specs.
This is just an update, MDTech was right on. I want to thank you for your help, it was the valve adjust that did it. My readings were well below the avg. after I did the adjustment. I can't believe no one that I took the truck to could diagnose the problem, well done my friend, you saved me a fortune!!
Cheers!!