MrEllis
Active Member
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.
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.