Chrysler49

Air mixture screw having no affect on the engine still shows something isn't quite right, but I'll worry about it next year.

Vacuum showed 14 at the idle. If I loosened the vacuum gauge to allow more air in the idle went up a bit, and the vacuum would set steady at 18. Perhaps my idle is too low? I raised the idle a bit, and the vacuum is right where it needs to be. I'd estimate the idle at 600-700 rpms, but the black exhaust stops and the car runs great. I think I'll call it good for now.

I removed the spring from the power valve. The idle seems to want to hang a bit before falling now, but when it settle I'm still getting too much sooty black exhaust. When idling around 2000rpms the exhaust appears relatively clean. I do have the square plug on the side of the intake, but nothing that screws in with which to attach my vacuum gauge. I'll have to go to the parts store tomorrow and attempt to either find or fabricate something. The plug size appears to be 11/16th, which hopefully isn't too much of an issue.

Rechecked points, verified timing, and even lowered the float to a point I know is a tad too low. Car runs alright down the road but is still burning way too rich, particularly at idle; vacuum port at the base of the carb is clear. I tried both advancing and retarding the timing a touch just to see what happened, and the car didn't like being anywhere but 0 degrees TDC at idle. Haven't found a way to properly vacuum test the carb, and the car doesn't have vacuum wipers. This has to be something to do with the carburetor, which baffles me considering it's been rebuilt and cleaned to a T several times over the past year. As I posted earlier, I haven't taken out the main vent tube and I'm still thinking this could be a part of my issue. I don't have the tool and it isn't easy to come by. Only place that I can find it is open Mondays and Tuesdays and that's it. Other than that I guess maybe I've got too high of fuel pressure coming through the rebuilt pump. Not being able to kill the car by seating the idle mixture screw at idle tells me it's in the carb.

Don't have a tach, so cannot be 100%. I aim for a low, but smooth idle. 450 is what the manual wants.

Watched that last year when I did my rebuild. I'm pretty sure that's where I ordered my kit from.

Car will start and stumble for a few seconds, but won't run without the cover and toothpick/tape over vacuum hole

I've got the gasket at the bottom of the step up piston chamber, but should there be some sort of gasket around the piston itself. The slots almost seem like they could hold an oring.

Set the timing. Car runs down the road nicely now, but still has a sooty exhaust at idle. Idle isn't perfect, and sounds a bit "burbly." Still cannot kill the car if I turn the idle mix screw all the way in, and my idle is set about as low as I can get it to go without killing the car. The step up piston is in good overall shape. I took it out and clean the sleeve out, and the spring seemed to be in good shape. The only possible place that could still be dirty would be the main jet tube. I don't have the special tool to remove and replace that once the rivet is out. My float seems to be a touch on the low side, but I guess my personal observation could be incorrect.

Will have help tomorrow setting timing. Hopefully that is the overarching issue here.

Cap is vented. Taking it off still results in black smoke at idle.

Haven't properly set the timing yet bit it's close enough to test drive a bit. Car seems to be running pretty well down the road, it's at idle I seem to be running really rich. Notice getting gas that the fuel cap sucks ALOT of air when unscrewing. Could I be having a venting issue? Cap is only a year old, but I suppose the backfire could have done something.

I know there is a gasket at the base of the step up piston, under the spring.

I see there is a plug you can unscrew in the manifold just below the carb. I'd guess that'd be a good place to connect into. Thing is absolutely drinking fuel now. Hard to believe timing being off would cause the thing to burn so much fuel. Exhaust is black and I'd estimate around 5 miles to the gallon if the fuel gauge is somewhat accurate. Idle is definitely off, and I can hear it missing. Won't have access to my timing light for a few more days.

Adding the spring to the distributor amounted to a lot of success. I once again have power at and above 50 mph, but it now definitely needs timed properly. Has a bit of surging when hanging at 50-55 mph, and it's still spouting black smoke out the tail pipe.