CO is killing me.

[MrEllis]

I have '67 Coronet someone put a 383 in years ago. It has an Edelbrock 1411/750 CFM. I don't know what it was tuned for but it ran very rich when I got it. I changed air filter, fuel filter and reset all the mixture screws and tuned it until it ran fine and just at the edge of lean, where it didn't ping or anything. I do not have a timing gun that works anymore but I have ordered a vac gauge and I just got a new fuel pressure gauge I'll add in-line this weekend. My car doesn't run as rich as before, but the CO emissions are bananas. At idle, if I walk around the car with a bit of a breeze, the CO reads 100-500+ PPM. Windows rolled up it's not bad but cruising and stop and go traffic I get sick. I've stopped driving it until i figure this out. It's not an exhaust leak (i couldn't find one and a mechanic who works on classics only couldn't find one), it's the exhaust itself.

Maybe I'm just old and suddenly can't tolerate exhaust. But my wife mentioned it after I took her for a ride and even my niece noticed. Classic CO signs, throat scratchy, headache, lungs hurt. Once I had that happened I stopped driving it. But even working on it I can tell still. And I know modern cars are better, but same day and location I could barely get 20-100 PPM out of a Challenger at the pipes with a 345. Sure, it's a modern car, but it read 0 walking around it. I'm not a mechanic by any means, I'm an IT guy, but I've never had this issue with classic cars before. I was hoping folks had ideas. Most of the posts focus on bad trunk seals and leaks, this a bit beyond that. I can't even get near the thing when it's running. It's a pretty looking war crime at this point.

1. Would a fuel pump at too high a pressure cause this?
2. I can't lean it much more without issues, would a smaller carb help?
3. PCV valve? (Is that valve twice?)
4. Maybe I can't drive a classic anymore?

I appreciate any advice. I'll worry about leaks and slipping a piece of paper in the trunk after I've toned down the exhaust at the pipe. Thanks for reading, all. I forgot to add, I haven't checked plugs yet. So that's on the list.

 

[Sahara]

This is interesting. Following.

 

[dadsbee]

My Bee would burn the hairs right out of your nose when I got it running after restoration and 14 years of storage. Ran just fine but burned your eyes. Holley with a cooked / dried out power valve

 

[khryslerkid]

Read your plugs

 

[70 sublime]

Does you exhaust come out the back under the bumper ?

 

[MrEllis]

Read your plugs

They read rich. But, I've leaned it since I got it. To the point where it's almost too lean on carb. Plugs could not be igniting fully, but car sounds like it's happy and idles well and is responsive to pedal. It's a cruiser, but it will still get up.

 

[MrEllis]

Does you exhaust come out the back under the bumper ?

Exhaust is clear but leaves some black. The car is rich still, lean had a different stink. It's also hard to tell what is old and what isn't after I leaned it.

 

[Kern Dog]

I'm a bit curious as to why you don't have a timing light but you do have an instrument to measure exhaust gases.
A timing light is a pretty basic tool that car guys need to have. I don't know anyone that has any hand held tool to measure emissions. I have an air/fuel meter in the car though.
Old cars, heck...any vehicle with no catalytic converters will have a different smell compared to newer cars.

 

[4mulas]

Perhaps your idle air mixture screws are fine but the jetting is way off so when you get on the gas the fuel is far too rich?

 

[Mackman]

What method are you using to determine lean or rich condition? A/F meter?

 

[twecomm]

Having a timing light is a must, vac gauge is good to have also. Knowing how to optimize your timing is critical.
Read this article : Tuning Tips My experience is that Edelbrock carbs run rich out of the box. Your carb size may be a bit much for a 383. Think you will need to re-jet the carb and play with the springs, not so difficult on an Edelbrock, they sell jet, rod & spring kits for doing this. It sounds like your air to fuel ratio is way off. You are never going to get exhaust as good as it is on a modern car where everything is continuously being optomized for maximum efficiency and fuel mileage, however you can certainly can improve your situation.

 

[1967coronet]

Another thing that gets over looked is the trunk seal.

 

[4speed68rt]

You probably need to tune your carburetor for the altitude that you are at. Probably change the rods and jets. The screws on the front are only for fine tuning. The Edelbrock manual tells you how to do it. It is hard to guess the timing correctly, you should set it with a timing light.

 

[Darter6]

Maybe I'm just old and suddenly can't tolerate exhaust.

I would agree. I have a totally stock 88 Ram D 350 gas engine pickup with a carb.
Last year for a one ton no cat truck. It stinks . Hydrocarbons increase the leaner the carb gets.
That was according to the local smog tech. It passed smog every year. My 2 cents..

 

[66 Sat]

Are you running Ported or Manifold Vacuum Advance?
I found my idle much cleaner on MVA and the stink in my garage after I back the car in is almost non-existent compared to running Ported. Less smell of exhaust on clothes too after driving.

 

[Nxcoupe]

Get a timing light. Set your timing to 34 total with vacuum advance disconnected. Adjusting idle mixture screws does very little to nothing for cruise and wot mixture. I would get a tuning kit for carb with jets and metering rods. Get a wideband and watch videos of how to use it. Read or watch videos about how to tune an edelbrock carb. You are going about it all wrong and expecting impossible improvements, given your methodology. By leaning idle out, it could make co worse.

 

[Jesse6869]

My charger runs rich, eyes burn i start to cough. Got to love it. One day I’ll work on carbs.

 

[MrEllis]

I'm a bit curious as to why you don't have a timing light but you do have an instrument to measure exhaust gases.
A timing light is a pretty basic tool that car guys need to have. I don't know anyone that has any hand held tool to measure emissions. I have an air/fuel meter in the car though.
Old cars, heck...any vehicle with no catalytic converters will have a different smell compared to newer cars.

I had a timing light, but never used it, it's broke I found out. I haven't had a car I could work on in years. I did networking and had gear to test air quality in weird places because someone gave it to me. I didn't realize there would be a test on that, sorry.

 

[MrEllis]

Get a timing light. Set your timing to 34 total with vacuum advance disconnected. Adjusting idle mixture screws does very little to nothing for cruise and wot mixture. I would get a tuning kit for carb with jets and metering rods. Get a wideband and watch videos of how to use it. Read or watch videos about how to tune an edelbrock carb. You are going about it all wrong and expecting impossible improvements, given your methodology. By leaning idle out, it could make co worse.

Sort of useful, thanks. I think. Your kindness shows through!

 

[MrEllis]

Having a timing light is a must, vac gauge is good to have also. Knowing how to optimize your timing is critical.
Read this article : Tuning Tips My experience is that Edelbrock carbs run rich out of the box. Your carb size may be a bit much for a 383. Think you will need to re-jet the carb and play with the springs, not so difficult on an Edelbrock, they sell jet, rod & spring kits for doing this. It sounds like your air to fuel ratio is way off. You are never going to get exhaust as good as it is on a modern car where everything is continuously being optomized for maximum efficiency and fuel mileage, however you can certainly can improve your situation.

Far as I can tell they are the ones that came with the carb. I've already used the chart provided by Edelbrock to order a set to run less rich. Following their instructions. I may get the #1906 though. Haven't pulled the trigger on a rebuild kit yet because hey, it's 50 bucks I could spend on a new carb. I was wondering if anyone had experienced this before, so far, it doesn't seem like it.