I went down and had a smog guy do a quick sniffer test to see where my 83sc motor is at and here are the results! What do they mean? The guy at the station said I had an exhaust leak but other than that the numbers were good! He couldn't tell me what that ment, lean or rich or good, probably because he was a test only guy and knows nothing???

Idle Numbers:

hc....75
co....1.07
c02..11.6
02....3.5
no....18

2400 RPM Numbers:

hc......40
co....0.47
c02..11.9
02.....3.8
no.....112

It means you have too much free time! Busy smog checking an exempt car. What's next? Add water to the ocean?

I just wanted to know if it is running lean so I didn't burn something up!!

They were just sitting around and did it for free so what the heck, why not!!!

It really won't tell you much about lean or rich

you have two rpm points, idle and 2400

to tell if lean you really need to be under load and at max rpm is where "lean" really matters.

so a chassis dyno hooked up to a wide band sensing unit is the test to tell you that.

OK so anyone have or know of a set up to test that in the East Bay Area?

I can tell you have an exhaust leak from all the smoke on your avatar - can barely see the car.

lol

McMark can test you throughout the RPM range and tell you whether you are rich or lean. He has an Innovate LM meter with a tailpipe sniffer. He can even do it under load as he puts it into your exhaust and clamps it in place. Probably cost you an hour of his shop time...

Idle and 2400 rpm numbers don't tell you a lot but if I recall correctly you don't have a cat or air injection on that engine. With the stock CIS system you have on your engine it is running a bit leaner at idle that I would set it to start with but not much.
About 1.5% CO is a good starting point for an engine intended to have a cat. If the CIS system is working correctly CO set at 1.5% at idle will keep you in a safe range under load. Without a cat you can go richer without a problem.

Jim

An exhaust leak will show a lean mixture.
Fix the leak before you test it and the results may be useful

according to my info the reference values are:

hc < 500
co < 3.0
co2 > 11.5

my actual values are:

hc = 184
co = 1.75
co2 = 13.7

for comparison, my 97 cherokee reference:

hc < 70
co < 0.5
co2 > 12

actual:

hc = 4
co =0.00
co2 =15.2

where is the leak?

I have not looked for the leak yet! It does not pop or back fire at all so it must be a small one closer to the muffler than the heads!

based on these numbers, what would make one think there is a leak?

While acceptable, idle 1.07 CO is a little fat at the tail pipe. I like mine to be .05 to .07 at idle with the O2 sensor system operational and the catalyst working well. If your cat is either dead or missing, 1.07 is maybe a little lean. You should pass a smog test pretty easily. I can't comment on the NOx numbers because we don't measure that in non-enhanced areas. If you don't have the lambda (O2 sensor) system and no cat, you're pretty lean. I'd look for 1.5% at idle, if it'll run that way. Once that's set, the 2500 RPM number is gonna fall wherever it wants to be, because you really can't set that.

The Cap'n

The motor is installed in my 914 and it is a complete 83 sc FI with o2 sensor and lambada. I do not have a cat and am running headers with a twin tip exhaust!

So you think it is a bit lean?

Here is what the exhaust looked like before installing the o2 sensor!