82 z28 with a 350 swap, 4 bbl edelbrock carb. Just got new cap&rotor, plugs, air filter.
2500 RPM TEST Standard Test
CO(%) 1.20 4.66
HC(PPM) 220 257

Idle Test Standard Test
CO(%) 1.20 8.24
HC(PPM) 220 1137

Oh yeah, and the car won't idle anymore..Pretty new to working on cars, any help is appreciated!

 

when you or who ever did the swap was the EGR, smog pump, or cat removed? from the looks of the readings you got their are a few things you can try.
1. step down your primary jet and your metering rods
2. check your timing
3. thin out your idle mixture
try these first along with making sure the factory emission equipment is hooked up and working properly at least for testing.
make sure the car is up to temp when you take it for testing.

 

I'm not sure actually, previous owner didn't do the swap either but as far as I know it doesn't have a cat. I heard since it was an 82 it didn't need one or something of the sort.
Also, someone else said it was running way too rich, would that be the carb? I'd like to avoid messing with jets if possible.
And how do I check timing? Sorry, pretty new to car maintenance/repair.
Thanks for the help!

 

yes running rich would be caused by the carb. On Edelbrock carbs its easy to change the jets and rods you just unbolt the top of the carb and every thing is right there. you first need to know two things what model carb you have and what is the altitude you live at. the model number is the 4 numbers stamped on the front left side of the carb on the bottom. If you dont have the tuning manual you can go to edelbrocks website and look it up it has a tunning section in it that will help you pick the right jets and rods.
for checking timing get a timing light and hook it up to the number one plug wire unplug the vacuum advance on the dist. and plug it. their should be a mark on the harmonic balancer and a pointer on the timing cover. set your timing to around 8 to 12 advanced and see if that helps.

 

You're running way too rich. A few things to keep in mind when tuning for emissions: CO is caused by rich fuel mixture only. To reduce CO, simply lean out AFR. I would start by adjusting idle mixture. That's just the idle mixture screws. As rich as idle is, that's probably your whole CO problem. HCs are unburned fuel. They are caused by ignition misfire, rich AFR, or lean AFR. Bringing your CO in line will probably reduce HCs considerably. If after adjusting idle mixture to reduce CO, you find that HC is still high, be sure that CO isn't too low. As I said, too lean will cause HCs to increase from lean msfire. Non catalyst cars will generally run about .5-.6% CO dialed in. Any less is too lean. When you've dialed in CO and HC as close as you can and HC is still too high, you can further reduce HCs by retarding timing a few degrees. This increases exhaust manifold temp and the hot manifolds burn the HCs out of the exhaust. If your vacuum advance is connected to manifold vacuum, try switching it to ported vacuum. Also, raising idle speed will reduce HCs. It is best to use a 4 gas analyser when tuning for emissions. Otherwise, you just have to best guess it and repeat the test until you pass. Keeping exhaust temps high by holding rpms at 2,000 or so while waiting in line at the test center will lower HC.

 

You live in Boise. Thats 2800 ft altitude for the Edelbrock tuning website. I'd start with leaning the idle mixture and see how that does. Might fix the idle problem too. Could be running so rich that it won't idle. All depends if it's raining Saturday & if you can work it in your schedule.

 

So after a visual the car doesn't have a catalytic converter. How might that affect:
A) idle - much reduced back pressure?
B) passing smog in Idaho?

 

Unless you're running aftermarket headers, I wouldn't worry about back pressure from dropping a cat. The biggest contributor to back pressure is the mechanical distance from the engine block to the tailpipe.

If you can't pass emissions, you might try mixing some ethyl based alcohol into your gas. shoot for 25% alcohol by volume. It's a risk to your engine, so do your research for your specific fuel delivery system and setup.

No SMOG tests here in MI, but I've read this works and I'm familiar with the science behind it. Seems to check out.

 

Only the Idaho DEQ can tell you whether they will pas you without a cat. In Oregon, depending on the tester, they would likely let you slide if you pass the sniff test. A cat will help you bring your numbers down. However, if your car runs very dirty, it will burn up the cat rather quickly.

 

....so glad I don't live in an area that has emissions testing....

BTW, to the OP, why not simply register the car in a different county?? To my knowledge, Boise (Ada Cnty) is the only area that does the testing in the state. I lived in Idaho Falls for many years (still have family there and in Pocatello) and there is no testing there, either.

 

There's an idea. I did that for years. Now I live where there is no testing.